How do you simplify #2x-9y+7x+20y#?
Jan 10, 2016
9x + 11y
To simplify the expression collect 'like terms'.
ie. collect together the terms which contain the same variable by adding or subtracting their coefficients.
so 2x + 7x - 9y + 20y = ( 2 + 7 )x + (- 9 + 20 )y
= 9x + 11y