Add 15 to a number then then multiply the result by 3 the answer is the same as subtracting 4 from the number and multiplying the result by 5

Answer 1

x = number

( x + 15 ) ∙ 3 = ( x - 4 ) ∙ 5

3 x + 45 = 5 x - 20

Subtract 3x to both sides

45 = 2 x - 20

Add 20 to both sides

65 = 2 x

2 x = 65

x = 65 / 2 = 32.5