I know it must be simple, but I just can't get it It's only the first step of a large question, so if you get me started i would be vury grateful indeed!
p.s: i know i have to merge the equation on the left by making a common denominator. i did it and then i flipped the second equation so it could be multiplied by the first, but the answer i get isn't what my friends say they have gotttennn......