In order to combine, you have to multiply the top equation by 2
so you get
8g + 10h = 8
8g - 10h = 4
---------------
16g = 12
g = 3/4 --> plug it in to solve for h
8(3/4)-10h = 4
6-10h=4
10h=2
h=1/5
Your result: g=3/4, h=1/5
Sa= 23.14r(r + h)
(sa)/(23.14r= r + h
h= (sa)/23.14r - r
h= (sa)-r^2/(23.14r)
Answer: f(3)=-20
Step-by-step explanation:
If you look at f(x) and f(3), you can see that 3 is in place of x. That means when x=3, what is f(x). You plug in x=3 into f(x) and solve.
f(3)=-2(3)²-2
f(3)=-2(9)-2
f(3)=-18-2
f(3)=-20
-25+-50=-75
because they lost 50 points that makes the 50 negative.