simplify -(3x - 4y) +x by combining like terms
-(3x - 4y) + x = -3x - (-4y) + x = -3x + x + 4y = -2x + 4y
\(-(3x - 4y) + x\)\(-3x - (-4y) + x\) \(-3x + x + 4y\)\(= -2x + 4y\)
