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.
I think you would times them to find the area which is 194 ft4
For A B and C, you just plug in the given number
A

B

C

And for D, you set the equation to 26 and solve for n

I had to use x instead of n, but for D n=7. :)