Ask Question
3 February, 14:12

4r+3=r+21

How do I do this?

+2
Answers (2)
  1. 3 February, 15:03
    0
    You first:

    4r+3-3=r+21-3

    4r=r+18

    4r-r=r-r+18

    3r=18

    3r/3=18/3

    r=6

    remember that what you do in one side, do it in the other
  2. 3 February, 15:19
    0
    Simplify: 4r + 3 = r + 21, then reorder the terms: 3 + 4r = r + 21.

    Reorder the terms 3 + 4r = 21 + r. Solve: 3 + 4r = 21 + r.

    Move all terms containing r to the left, all other terms to the right.

    Solving for variable 'r'.

    Add '-1r' to each side of the equation. 3 + 4r + - 1r = 21 + r + - 1r.

    Combine like terms: 4r + - 1r = 3r 3 + 3r = 21 + r + - 1r

    Combine like terms: r + - 1r = 0 3 + 3r = 21 + 0 3 + 3r = 21

    Add '-3' to each side of the equation. 3 + - 3 + 3r = 21 + - 3

    Combine like terms: 3 + - 3 = 0 0 + 3r = 21 + - 3 3r = 21 + - 3

    Combine like terms: 21 + - 3 = 18 3r = 18

    Divide each side by '3'. r = 6 Simplifying r = 6
Know the Answer?