Answer:
Step-by-step explanation:
If y = 2x + 1, then dy/dt = 2(dx/dt).
If y = 2x + 1, then y = 2(40) + 1 when 40 is substituted for x. y = 81.
(a) if dx/dt = 3, find dy/dt when x = 4:
Replacing dx/dt with 3 in dy/dt = 2(dx/dt) yields dy/dt = 2(3) = 6.
(b) if dy/dt = 2, find dx/dt when x = 40:
Replacing dy/dt with 2 in dy/dt = 2(dx/dt) results in 2 = 2(dx/dt), so dx/dt must be 1.
Answer:
50 people
Step-by-step explanation:
100-70 is 30. 30-20 is 10. 60-10 is 50.
Answer:
x = minus two
Step-by-step explanation:
5x+3 = 2x-3
5x-2x = -3-3
3x = -6
x = -6÷3
x = -2
Answer:
x = -2.5 ± √14.25
Step-by-step explanation:
Add 5x to prepare for "completing the square."
x² +5x = 8
Add the square of half the x-coefficient:
x² +5x + 2.5² = 8 + 2.5²
(x +2.5)² = 14.25
Take the square root.
x +2.5 = ±√14.25
Subtract 2.5.
x = -2.5 ± √14.25 ≈ {-6.27492, 1.27592}