Look at deonomators
assuming that the deonomenators are 5x+15y and 2x+6y
find their LCM
factor
5x+15y=5(x+3y)
2x+6y=2(x+3y)
LCM=10(x+3y)=10x+30y
multiply 2/(5x+15y) by 2/2=4/(10x+30y)
multiply 1/(2x+6y) by 5/5=5/(10x+30y)
if we add them
9/(10x+30y)
Are you trying to simplify? if so, the answer is 13u/6
Please, write "x^3" for "the cube of x," not "x3." "^" denotes exponentiation.
Then you have g(x) = x^3 - 5 and (I assume) h(x) = 2x - 2.
1) evaluate g(x) at x = -2: g(-2) = (-2)^3 - 5 = -8 - 5 = -13
2) let the input to h(x) be -13: h(-13) = 2(-13) - 2 = -28 (answer)