-4(x+2)=-40 — step-by-step solution

Let's solve in

ℝ

-4 \cdot (x + 2) = -40

ⓘ Expand by multiplying each term inside the parentheses:

- 4 \cdot (x + 2)

- (4 x + 8)

- (4 x + 8) = -40

ⓘ A minus sign before a parenthesis changes the sign of each of its terms:

- (4 x + 8)

- 4 x - 8

- 4 x - 8 = -40

ⓘ We gather the terms in

x

on the right and the other terms on the left

- 8 + 40 = 4 x

ⓘ Start from

-8

and move forward

40

on the number line, going past zero:

- 8 + 40

32

32 = 4 x

ⓘ Both sides are divided by

4

x = \frac{32}{4}

ⓘ We simplify the fraction by dividing the numerator and the denominator by

4

, their greatest common divisor:

\frac{32}{4}

8

▶Solution obtained:

x = 8