Need help quick easy problem to solve pls help!

C

Step-by-step explanation:

12b + 30f = 240

7b + 10f = 125

Multiply the second equation by -3

12b + 30f = 240

-21b -30f = -375

Add up the two equations

-9b = -135

b = $15

Substitute this value in one of the two equations

12 * 15 + 30f = 240

180 + 30f = 240

30 f = 60

f = $2

question 1 is 8, question 2 is 9, question 3 is 24

step-by-step explanation:

now, the numbers they give you at the top are the key. from there, you just have to plug and chug! let's try 1, 2, and 3!

key: a=3, b=5, c=6

1. a+5

remember, a=3, so we plug that in to get 3+5=8

2. 15-c

c=6, so we plug that in to get 15-6=9

3. 4b

b=6, so we plug it in to get 4*6=24

time to try the rest on your own! if you put the answers below in a comment, i'll check them for you!

a) y = -3x +2

b) y = 1/2x -6

these 2 can be combined into one equation.

-3x +2 = .5x -6

8 = 3.5x

x = 8 / 3.5 = 2.2857142857

y = -3 * (8 / 3.5) +2

y = (-24 / 3.5) + 2

y = -4.8571428571

step-by-step explanation: