2/5 = m / 70
cross multiply because this is a proportion
(5)(m) = (2)(70)
5m = 140
m = 140/5
m = 28 <===
it will take Dominic 48 minutes to go 12 miles because it took him 4 minutes every mile so you just multiply 4 times 12
Answer:
x = ±√11 +2
Step-by-step explanation:
Given in the question an equation,
x²- 4x - 7 = 0
Step 1
take 7 to the right side of equation
x²- 4x = 7
Step 2
To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of b, the coefficient of x
2ab = -4x
2xb = -4x
b = -2
Step 3
Take square of b and add it to each side of the equation.
x²- 4x + (-2)²= 7 + (-2)²
x²- 4x + 4 = 7 + 4
x²- 4x + 4 = 11
Step 4
Factor the perfect trinomial square
(x−2)² = 11
Step 5
take square root on both sides
√(x−2)² = √11
(x-2) = ±√11
x = ±√11 +2
Answer:
≈ 4,22 m
Step-by-step explanation:
volume = 20000L = 20000 dm^3 = 20 m^3
diameter = 2,4m
the volume of a cilinder is π * r^2 * h (height)
20 = π * 1,2^2 * h
h = 
≈ 4,42 m
