We've already evaluated expressions with one variable. Now it's time to do it with two variables.

How to evaluate an expression with two variables

Let's say we want to evaluate the expression 10+2p3r10 + 2p - 3r. Well, first we need to know the values of pp and rr. For example, to evaluate the expression when p=4\blueD {p = 4} and r=5\goldD{r = 5}, we just replace p\blueD p with 4\blueD 4 and r\goldD r with 5\goldD 5:
=10+2p3r\phantom{=}10 + 2\blueD p - 3\goldD r
=10+2435=10 + 2\cdot\blueD 4 - 3 \cdot \goldD5
=10+815=10 + 8 - 15
=3=3
So, the expression 10+2p3r10 + 2p - 3r equals 33 when p=4p = 4 and r=5r = 5.

Now, let's practice