Answer:
Answers B, E and F (1, 5 and 6).
Step-by-step explanation:
In an exponential equation, (y=ab^x), the "b" value must be a decimal less than 1 (but greater than 0) for it to be considered an exponential decay function. Only equations B, E and F have a "b" value that fits this criteria.
11
5x+15+20=90
5x+35=90
-35 from both sides
5x=55
divide both sides by 5
x=11
200.96
3.14 x (8x8) = 200.96
2.4 or 12/5 or 2 2/5