Pre-Algebra Questions.?

Question

18. Write numerator 21 divided by denominator 28 in simplest form.

19. Simplify numerator negative 21 divided by denominator negative 66

20. Solve for x. 11x + 4x = -15

Answer 1

18) both of those numbers are divisible by 7.  it can be rewritten as 7*3  /  7*4.  The 7's cancel, so you get 3/4

19) these numbers are both divisible by 21.  it can be rewritten as -21*1  /  21*3.  The 21's cancel, so you get -1/3

20)  add the numbers with the variables together.  you get 15x = -15.   Divide both sides by 15 in order to get x, the variable, by itself.  that leaves you with x = -1

Hope this helps