It increased by $3.15
The new monthly cost is $48.15
4(x - 8) = (2)(5)
4x - 32 = 10
4x = 42
x = 10.5
Answer:
(4x+5)(-3x-1) = -12x²-19x-5
Option A:
(-16x² + 10x - 3) + (4x² - 29x - 2) = -12x²-19x-5
Option A is correct.
Option B:
3(x - 5) - 2(6x² + 9x + 5) = -12x²-15x-25
Option B is wrong.
Option C:
2(x - 1) - 3(4x² + 7x + 1) = -12x²-19x-5
Option C is correct.
Option D:
(2x² - 11x - 9) - (14x² + 8x - 4) = -12x²-19x-5
Option D is correct.
Dy/dx = dy/dt / dx/dt
dy/dx = 12x^2 + 4
when x = 2 , dydx = 52
52 = dy/dt / 3
so dy/dt = 156 (answer)