To determine which number from the set {15, 25, 35, 55} makes the equation y + 15 = 40 true, we can substitute each number and check if the equation holds.
Substituting y = 15:
15 + 15 = 40
30 ≠ 40
Substituting y = 25:
25 + 15 = 40
40 = 40
Substituting y = 35:
35 + 15 = 40
50 ≠ 40
Substituting y = 55:
55 + 15 = 40
70 ≠ 40
Since the equation y + 15 = 40 is only true when y = 25, the number 25 from the set {15, 25, 35, 55} makes the equation true.
Using substitution, which number from the set {15, 25, 35, 55} makes the equation y + 15 = 40 true?
1 answer