Introductory Algebra for College Students (7th Edition)

$x=-2$
$3x+2x+64=40-7x$ $5x+64=40-7x$ $5x+7x+64=40$ $12x+64=40$ $12x=40-64$ $12x=-24$ $x=\frac{-24}{12}$ $x=-2$ Check the answer. 3(-2)+2(-2)+64=40-7(-2) -6+(-4)+64=40-(-14) -10+64=40+14 54=54