c = d + 3
In this equation, the variable c represent's Carter's score, and the variable d represents Denise's score. Because Denise scored 3 fewer points than Carter, that means that Carter scored 3 more points than Denise. Therefore, d, or Denise's score, is equal to c, or Carter's score, if you add 3. Now, let's substitute in Denise's score of 18.
c = 18 + 3 Substitute
c = 21 Add
Carter's score is 21. If we wanted to check that, we could simply reverse the equation.
d = c - 3 Because Denise scored three fewer points than Carter, his score equals Carter's score minus 3.
d = 21 - 3 Now, let's substitute in the answer we got for Carter's score.
d = 18 Yep! The question says that Denise scored 18 points, so the answer we got is correct.
