## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$x=-15$
By combining like terms and using the properties of equality, the solution to the given equation, $10-3x=x-2x+40$, is \begin{array}{l} -3x-x+2x=40-10 \\\\ -2x=30 \\\\ x=\dfrac{30}{-2} \\\\ x=-15 .\end{array} CHECKING: \begin{array}{l} 10-3(-15)=(-15)-2(-15)+40 \\\\ 10+45=-15+30+40 \\\\ 55=55 \text{ (TRUE)} .\end{array} Hence, the solution is $x=-15$.