A bakery is having a grand opening sale. They are selling cookies for \$1.50 each and muffins for \$2.25 each.

Emily goes to the bakery and buys 4 cookies and 3 muffins. We can represent her purchase like this:

We can use the expression 1.50c+2.25m to represent the cost for buying different amounts of cookies and muffins.

We can find the cost of Emily's purchase by using **substitution**. To find the value of (or **evaluate**) the expression with substitution, we will replace the amount of each item Emily bought with the variables in the the expression. This will look like this: 1.50\left(4\right)+2.25\left(3\right)

Now, we can use what we know about the order of operations and properties of real numbers to evaluate the expression to find the total that Emily spent.

\displaystyle \text{Total Spent} | \displaystyle = | \displaystyle 1.50\left(4\right)+2.25\left(3\right) | Begin with the expression |

\displaystyle = | \displaystyle 6+6.75 | Evaluate the multiplication | |

\displaystyle = | \displaystyle 12.75 | Evaluate the addition |

The total cost of Emily's purchase is \$12.75.

Evaluate \dfrac{3}{4}g + 20-\dfrac{1}{2}g-h, when h=7 and g=-8.

Worked Solution

Evaluate\text{ }a\left(b-c\right)−3ac when a = -1.25, b = 13.4, and c = 7.3

Worked Solution

The area, A, of a circle is given by the formula: A=\pi r^{2}

where r is the length of its radius.

Find the area of a circle with a radius of 12 \text{ ft}. Use 3.14 for the value of \pi.

Worked Solution

Idea summary

To evaluate expressions for given values, you will first substitute the values into the expression. Next, we use order of operations to evaluate expresion.