Evaluate each of the following expressions for the given value:
m - 2 for m = - 7
x - 2 for x = 8
7 a + 18 for a = - 3
8 x + 4 for x = 2
45 - 7 x for x = 6
\dfrac{n}{9} for n = 8
\dfrac{6}{w} for w = 3
\dfrac{4 k}{5} for k = 15
\dfrac{r}{5} for r = - 20
\dfrac{15}{r} for r = - 3
\dfrac{5 c}{- 36} for c = - 4
\dfrac{4 y - 1}{y - 1} for y = 6
18.6 - 3 x for x = 4.1
5.1 + v for v = - 10
Evaluate each of the following expressions for the given value:
y + 5 for:
y = 3
y = 6
m + 6 for:
m = - 5
m = -7
\dfrac{45}{2 n} for:
\dfrac{- 36}{5 n} for:
Evaluate each of the following expressions for the given value:
y^{2} for y = 4
r^{2} for r = - 2
7 a^{2} for a = - 3
3 x^{2} + 5 for x = 2
25 - z^{2} for z = 8
5w^{3} for w = -2
\dfrac{z^{3}}{z^{2} - 6} for z = 4
\dfrac{3 x + 2}{x^{2} - 4 x - 12} for x = 7
Evaluate x^{2} - 9 x + 18 for:
x = 2
x = 4
If x = 3, evaluate:
3 x^{2}
\left( 4 x\right)^{2}
- 2 x^{2} + \left( 3 x\right)^{2}
Find the largest whole number that can be substituted to p so that the expression 81 - p^{2} is positive.
Evaluate each of the following expressions for the given values:
a + b for a = 5 and b = 1.1
a - b for a = - 2 and b = 7.9
u + v + 25 for u = 32 and v = 48
- 9 m n + 2 n for m = - 7 and n = 8
s \left(12 - t\right) for s = - 3 and t = 10
4 r \times 3 s + 38 for r = - 5 and s = 3
\dfrac{4 a \times 5}{9 b} for a = 7 and b = 21
\dfrac{2 a \times 9}{5 b} for a = 25 and b = - 2
\dfrac{a}{1 - r} for a = 3 and r = \dfrac{1}{10}
5 a \times 6 b for a = \dfrac{1}{5} and b = 4
6 r \times 4 s for r = - \dfrac{1}{6} and s = 7
\dfrac{y+z}{2z} for y = 0.8 and z = 0.2
Evaluate each of the following expressions for the given values:
m n for:
m = 7 and n = 9
m = \dfrac{1}{8} and n = 72
m = 4 and n = 3.5
r s for:
r = 3 and s = - 5
r = \dfrac{1}{5} and s = - 35
r = - 5 and s = 3.2
3 x - 4 y for:
x = 4 and y = 8
x = \dfrac{1}{3} and y = 5
x = 2 and y = 7.8
6 x - 3 y for:
x = 5 and y = 5
x = 7 and y = 4
x = 8 and y = \dfrac{1}{3}
x \left( 3 y + 4\right) + 42 for:
x = 4 and y = - 2
x = - 43 and y = - 1
x = 10 and y = 5
Evaluate \dfrac{11 s - 39}{3 r} when r = - 1.6 and s = 2.8, correct to three decimal places.
Evaluate each of the following expressions for the given values:
5 j k l for j = 4, k = 3 and l = 5
6 a - 3 b + 4 c for a = 8, b = 6, and c = 7
w + z + y for w = 26, z = -27, and y = -39
\left(u + v\right) \left(w - y\right) for u = 5, v = 8, w = 2 and y = 10
Evaluate each of the following expressions for the given values:
u + v w for:
u = 59, v = 3 and w = 15
u = 14, v = 5.5 and w = 3.6
w + z y for:
w = - 60, z = 7 and y = 8
w = - 98, z = 10 and y = 11
\dfrac{a b}{5 c} for:
a = 2, b = 3 and c = 4
a = 4, b = 16 and c = 2
\dfrac{p q}{- 8 r} for:
p = 5, q = - 3 and r = - 9
p = - 9, q = 21 and r = 3
Evaluate each of the following expressions for the given values:
\left( r h\right)^{2} for r = 2 and h = 3
\left( p q\right)^{2} for p = 6 and q = - 2
v^{2} + u for u = - 49 and v = 2
x \left(2 - 4 y^{2}\right) for x = - 2 and y = - 2
a \left(b - 13\right) + b^{2} for a = - 9 and b = 10
\dfrac{m v^{2}}{2} for m = 8 and v = - 15
If m = - 3 and n = 4, evaluate:
m n - \left(m - n\right)
m^{2} + 9 n
Adam sells chocolates to raise money for charity. Each chocolate sold earns \$6 for the charity.
If Adam sells q chocolates, write an algebraic expression for the amount of money he raises.
Find the amount raised if he sold 4 chocolates.
Find the amount raised if he sold 5 chocolates.
Is it possible to raise exactly \$50 if Adam sells chocolates at \$6?
Valentina's hens produce 5 eggs each day.
If Valentina collects the eggs from her hens for y days, write an algebraic expression for the total number of eggs.
Find the number of eggs Valentina will have after 30 days.
John sells chocolates in two different sized boxes. He also sells bulk amounts in packages to supermarkets.
- Small boxes contain x chocolates
- Large boxes contain y chocolates
- Packages contain k boxes of chocolates
Write an algebraic expression for the total number of chocolates required for each or the following orders:
2 small and 5 large boxes.
3 small boxes and five indivudual chocolates.
One bulk package of large boxes.
5 packages of small boxes and 3 packages of large boxes.
If small boxes contain 10 chocolates, large boxes contain 20 chocolates and packages contain a dozen boxes, find the total number of chocolates required for the each order in part (a).
Justin uses a watering can to give each of his plants an equal amount of water.
If his watering can contains m\text{ mL} of water and he has n plants, write an algebraic expression for how much water is given to each plant.
As n increases, do the plants receive more or less water?
Robert visits a carnival that costs \$5 to enter, and each ride costs \$1 per person.
If Robert decides to go on b rides, write an algebraic expression for the total amount he spends at the carnival.
If Robert goes on 6 rides, calculate the amount of money he spend in total.
At a movie screening x adults and y children attend.
Write an algebraic expression for the total number of people who attended the screening.
The price of adult tickets are \$12 and children's tickets are \$8, write an expression for the total takings on ticket sales for the screening.
If 20 adults and 25 children attended, calculate the total takings on ticket sales for the screening.
At an event there are a motorcycles and b cars. Assuming all the motorcycles have two wheels and all the cars have four wheels:
Write an algebraic expression for the total number of wheels at the event.
Write an algebraic expression for the average number of wheels per vehicle at the event.
Find the average number of wheels per vehicle if there were 8 motorcycles and 32 cars at the event.
Vanessa has \$700 in her bank account. She only uses the account to pay her mobile phone bill each month.
If each monthly bill is \$14, write an algebraic expression for how much Vanessa has in her account after c months.
Find the amount of money she will have in her account after she pays her bill for 4 months.
Laura has a piggy bank in which she collects 20c and 50c coins. After some time, she loses track of how many coins are in the piggy bank.
Let m represent the number of 20c coins and n represent the number of 50c coins. Write an algebraic expression for the total value of Laura’s coins in cents.
Laura breaks her piggy bank and discovers that she has thirteen 20c and twenty-seven 50c coins. Find the total value of these coins in dollars.
Water is dripping from a tap into a large bucket, so that:
After 1 hour, the water level in the bucket is 5 cm
After 2 hours the water level is at 10 cm
After 3 hours the water level reaches 15 cm
If the tap continues to leak at the same rate and stops after a hours, write an algebraic expression for the water level in the bucket at this time.
If the tap stopped leaking after b minutes, write an algebraic expression for the water level in the bucket at this time.
If the tap stopped leaking after 3.5 hours, calculate the water level in the bucket at this time.