15. First Distribute
-6x-4 = 2X + 6
Add 6X on both sides
-4 = 8x+6
Subract 6 on both sides
8x=-10
Divide by 8 on both sides
X = -10/8 = -5/4
16. -13
17. Cross Multiplication
32 = 3X-3
Add 3 on both sides
35 = 3X
Divide by 3 on both sides
35/3 = X
18. Can't see the whole picture
19. Add 7 on both sides
6N = 42. Divide by 6
N = 7
20. 2x+6=-x+1. ---- I cross multiplied
2x+5=-x. ---- I subract 1 on both sides
-3x = 5. ----- Subract 2X
X=5/-3 ---- I divided it by -3
Divide both sides by 2.
4/2=2
10/2=5
2/5
(ax-by)²+(bx+ay)²
a²x²-2axby+b²y²+b²x²+2axby+a²x²
a²x²+b²x²+b²y²+a²x²
(a²+b²)x²+(a²+b²)y²
(a²+b²)(x²+y²)
Answer:
A. A number divided by three minus fifteen.