First, you know that 3/4 = .75. Now we can distribute. multipy -10*.75. Then multiply .75*2/5. Add those two answers together to get your final answer.
16/21 is the correct answer
So WX is 7y +4 and XY is 21, and when you add those lines you get the whole thing, which is 12y so write that like an equation
12y = 7y+4+21
12y = 7y+25
5y = 25
y = 5