3(-2x + 20) + 8(x + 12) = 92
use distributive property to remove parentheses:
6x + (-60) + 8x + 96 = 92
can also be written as:
6x - 60 + 8x + 96 = 92
combine like terms:
14x + 36 = 92
get the variable on one side:
14x + 36 - 36 = 92 - 36
14x = 56
divide both sides by 14:
14x/14 = 56/14
x = 4
check your work by substituting 4 in for x in the original equation:
-3(-2(4) + 20) + 8(4 + 12) = 92
-3(-8 + 20) + 8(16) = 92
24 + (-60) + 128 = 92
24 + 128 - 60 = 92
152 - 60 = 92