Four times the sum of 8 and some number is 4. What is the number?

Step-by-step explanation:

Let the number be x.

Dividing both sides by 4,

Subtracting 8 from both sides,

The number is -7.

Step-by-step explanation:

Let the unknown number be x

Expand

Collect like terms and simplify

Divide both sides of the equation by 4

Simplify

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i

it would take 7/10 of an hour too fill the pool.

step-by-step explanation: