Which expression is equivalent to 2x-9+7x?

Nov 30, 2016

$9 x - 9$ or $9 \left(x - 1\right)$
$2 x - 9 + 7 x \to 2 x + 7 x - 9 \to \left(2 + 7\right) x - 9 \to 9 x - 9 \to$
$9 \cdot x - 9 \cdot 1 \to 9 \left(x - 1\right)$