15-4+8=? 5x, x=3. 5x3=15... 2y,2x2=4... 4z, 4x4=8
15-4=11+8=19.. sorry if this isnt correct, this is how id do it. when a number and a letter are together in algebra, you multiply them. you take your final probuct of multiplying the number and the letter, then you add/subtract/multipy/divide, what ever you have, and BAM! theres your answer right there
