What this dont get it

Step-by-step explanation:

All this question is asking you to do is simplify the given expression by combining like terms.

The point of combining like terms is that you can only combine, well, like terms. Like terms are terms that have the same variables and are raised to the same power. This means that in this case, we can't combine and because is attached to a variable. However, we can combine 6 and -3 because they are like terms; neither is attached to a variable. So, you end up with .

I hope this helps!

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6