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4.02 Substituting into algebraic expressions

Worksheet
Substitution
1

Evaluate y + 5 when:

a
y = 3
b
y = 6
c
y = -2
d
y = -10
2

Evaluate \dfrac{45}{2 n} when:

a

n = 9

b

n = 47

c

n = -10

d

n = -3

3

Evaluate:

a

9 + m when m = 3

b

x - 2 when x = 8

c

8 - c when c = 1

d

3 k when k = 4

e

5 v when v = 6

f

9 p when p = 2

g

\dfrac{n}{9} when n = 8

h

\dfrac{6}{w} when w = 3

i

6 n \times 10 when n = 2

j

3 c + 9 when c = 6

k

8 x + 4 when x = 2

l

45 - 7 x when x = 6

m

18.6 - 3 x when x=4.1

n

\dfrac{5 k}{24} when k = 8

o

\dfrac{15}{8 k} when k = 3

p

\dfrac{4 k}{5} when k = 15

4

Evaluate:

a

y^{2} when y = 4

b

7 y^{2} when y = 5

c

3 x^{2} + 5 when x = 2

d

\dfrac{b^{2}}{4} when b = 3

5

If x = 3, evaluate:

a

3 x^{2}

b

\left( 4 x\right)^{2}

c

x^{3} - 2x^{2}

d

- 2 x^{2} + \left( 3 x\right)^{2}

6

Evaluate x^{2} + 6 x + 9 when:

a

x = 2

b

x = 5

c

x = 8

d

x = \dfrac{1}{2}

7

Evaluate u + v when:

a

u = 7 and v = 3

b

u = 3 and v = 16

c

u = -2 and v = -8

d

u = -15 and v = 35

8

Evaluate 6 x - 3 y when:

a

x = 5 and y = 5

b

x = 7 and y = 4

c

x = 1.5 and y = 3.5

d

x = 8 and y = \dfrac{1}{3}

9

Evaluate m n when:

a

m = 7 and n = 9

b

m = 4 and n = 3.5

c

m = 1.5 and n = 4.2

d

m = \dfrac{1}{8} and n = 72

10

Evaluate:

a

a - b when a = 9 and b = 5

b

a + b when a = 5 and b = 1.1

c

u + v + 25 when u = 32 and v = 48

d

3 y + 5 w when y = 6 and w = 5

e

6 x + 4 y + 6 when x = 3 and y = 5

f

4 x - 2 y - 6 when x = 3 and y = 2

g

4 x y when x = - 6 and y = - 5

h

- 4 \left(s - t\right) when s = 6 and t = 15

i

\dfrac{a}{b} when a = 56 and b = - 8

j

\dfrac{m n}{15} when m = 12 and n = 20

11

Evaluate:

a

k r when k = 5 and r = 6

b

3 r s when r = 4 and s = 5.6

c

5 a \times 6 b when a = \dfrac{1}{5} and b = 4

d

a b - 10 when a = 7 and b = 6

e

2 m \times 3 n + 37 when m = 4 and n = 5

f

3 y \times 5 w - 209 when y = 4 and w = 5

g

\dfrac{4 a \times 5}{9 b} when a = 7 and b = 21

h

2 y \times 5 w \times 3 when y = 4 and w = 3

i

\left( r h\right)^{2} when r = 2 and h = 3

j

4 y w + 9 w when y = 9 and w = 4

12

Evaluate \dfrac{a b}{5 c} when:

a

a = 2, \, b = 3, and c = 4

b

a = 4, \, b = 16, and c = 2

c

a = 2.5, \, b = 8, and c = 4

d

a = 1.4, \, b = 10, and c = 3.5

13

Evaluate u + a t when:

a

u = 18, \, a = 2, and t = 4

b

u = 37, \, a = 2, and t = 14

c

u = 50, \, a = 11.5, and t = 4

d

u = 10, a = \dfrac{9}{4}, and t = \dfrac{4}{3}

14

Evaluate u + v w when:

a

u = 59, \, v = 3, and w = 15

b

u = 14, \, v = 18, and w = 22

c

u = 14, \, v = 5.5, and w = 3.6

d

u = 4.2, \, v = 1.5, and w = 8

15

Evaluate:

a

a + b + c when a = 10, b = 15, and c = 11

b

x - y - z when x = -4, y=5 and z = 6

c

3 j + 5 k + 6 l when j = 3, \, k = 8, and l = 7

d

6 a - 3 b + 4 c when a = 8, \, b = 6, and c = 7

e

a b c when a = 8, b = 9, and c = 6

f

2pqr when p = 3, q = 4, and r = 5

g

p + q + r when p = 5, q = 9, and r = 6

h

5 j k l when j = 4, k = 3 and l = 5

Applications
16

The perimeter of a triangle is defined by the formula P = p + q + r.

Find P if the length of each of its three sides are p = 17\text{ in},\,q = 16\text{ in} and r = 14 \text{ in}.

17

For many three dimensional shapes, we can find the number of edges, E, on the shape by using the formula E = V + F - 2 where V is the number of vertices and F is the number of faces.

Find the number of edges of a three dimensional shape which has:

a

4 vertices and 4 faces

b

7 vertices and 7 faces

c

8 vertices and 6 faces

d

12 vertices and 20 faces

18

The area, A, of triangle is given by the formula:

A = \dfrac{1}{2}bh

where h is the height of the triangle and b is the length of its base.

a

Find the area of a triangle that has a base of 7 \text{ ft} and a height of 5 \text{ ft}.

b

Find the area of a triangle that has a base of 25 \text{ cm} and a height of 16 \text{ cm}.

c

Find the area of a triangle that has a base of 48 \text{ in} and a height of 28 \text{ in}.

d

Find the area of a triangle that has a base of 16.5 \text{ in} and a height of 24 \text{ in}.

19

Energy can be measured in many forms. A quantity of energy is given in units of Joules (\text{J}). The kinetic energy, E, of an object in motion is calculated using the formula:

E = \dfrac{m v^{2}}{2}

where m is the mass of the object in kilograms and v is the speed of the object in meters per second.

Find the kinetic energy, E, of an object with a mass of 6 \text{ kg}, traveling at a speed of 19 \text{ m/s}.

20

What is the largest whole number value that you can substitute for p so that the expression 81 - p^{2} is positive?

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Outcomes

MA.6.AR.1.3

Evaluate algebraic expressions using substitution and order of operations.

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