So I’ll do question 3. So normally you see f(x)= something plus x (something like that) you see it as a function of x.
So that notation of f(-1) means the function of -1. Which means you need to sub in -1 for x.
f(x)=-5x+5
f(-1)=-5(-1)+5
Negative times a negative is a positive
f(-1)=5+5
f(-1)=10
3x+8.5 =2.5x + 14.5
subtract 2.5x from each side
.5x + 8.5 = 14.5
subtract 8.5 from each side
.5x =6
multiply by 2
x =12
at 12 weeks they will be the same height
Choice B
Divide $2769 by $9 and you get 306.6 but you can’t just buy .6 of a toy so that leaves you at 306 whole toys and 306x9 is $2754 so you would have $15 leftover