-40+2n=4n-8(n+8)
Let's solve in ℝ: -40 + 2n = 4n -8·(n + 8)
ⓘ Expand by multiplying each term inside the parentheses: -8·(n + 8) = -(8n + 64)
-40 + 2n = 4n -(8n + 64)
ⓘ A minus sign before a parenthesis changes the sign of each of its terms: -(8n + 64) = -8n -64
-40 + 2n = 4n -8n -64
ⓘ Like terms are grouped by adding their coefficients: 4n -8n = -4n
-40 + 2n = -4n -64
ⓘ We add 40 to both sides■Start from -64 and move forward 40 on the number line, getting closer to zero: -64 + 40 = -24
2n = -4n -24
ⓘ We add 4n to both sides
2n + 4n = -24
ⓘ Like terms are grouped by adding their coefficients: 2n + 4n = 6n
6n = -24
ⓘ Both sides are divided by 6
n = -246
ⓘ We simplify the fraction by dividing the numerator and the denominator by 6, their greatest common divisor: -246 = -4
▶Solution found: n = -4