Answer:
1065
Step-by-step explanation:
57-42×-3-21
Answer: 16)
(17)
(18)
(19) 3x - 18
<u>Step-by-step explanation:</u>
Inverse is when you swap the x's and y's and then solve for y
16) Given: y = x²
Swapped: x = y²

17) Given: y = 2x + 4
Swapped: x = 2y + 4
x - 4 = 2y

18) Given: y = (x + 2)²
Swapped: x = (y + 2)²
√x = y + 2

19) Given: 
Swapped: 

3(x - 6) = y
3x - 18 = y
Answer:
B
Step-by-step explanation:
I've taken a picture of the way I solved it.
I think its c. Not really sure but yeah
3x + 1 + 5x = 7 + 15 + 7x
8x + 1 = 22 + 7x
x = 21