Remember: -a × -b = positive ab / +ab a × b = positive ab / +ab -a × b = negative ab/ -ab a × -b = negative ab / -ab Where ab is the product of the two numbers & - or + are the signs.
a) 5(2x+3y) -4(3x-5y) = 10x + 15y -12x + 20y = 10x - 12x + 15y + 20y = -2x + 35y = 35y - 2x [I've been told that most people prefer the positive number in front rather than the negative number]