How do i solve 15=16x-11x

You need to isolate x, which means you need to get it alone. 16x and 11x are like terms because they both have an x, do subtract them. 16-11=5. So 15 = 5x

Then to turn 5x into x, divide by five. This is because 5/5 is 1, and 1x is x. Divide both sides, so

X = 3