If it is 7 over 8x then the answer is 1 over 16(1/16), but if the x is in the numerator (on top) or separate from the 7/8 then you are right.

In the second problem, you have to find a common denominator so you can add the fractions together. The lowest common denominator is 20, so multiply x/4 by 5/5 and then multiply 3x/5 by 4/4. Now you can add the two fractions and solve the equation the same way you did the first one.

Similar work in the third problem. Here, multiply all the terms by 3, giving you 18a + 4 = -42. Then solve it. The answer will have a fraction in it.

To do x/4 + 3x/5 = 17, multiply all 3 things by the common denominator; this gets rid of the fractions. (it’s 20)

20(x/4) = 5x; 20(3x/5) = 12x; 20(17) = 340 so you have

5x + 12x = 340

17x = 340

now divide by 17

x = 20

Similar for next one, multiply all 3 by 3

18a + 4 = – 42 then subtract 4 and divide by 18