Solve the equation. √15x+18=5x

Square both sides:

15x + 18 = 25x²

25x² - 15x - 18 = 0

25x² - 30x + 15x - 18 = 0

5x (5x - 6) + 3 (5x - 6) = 0

(5x - 6) (5x + 3) = 0

x = 6/5, x = - 3/5

Check for extreneous solutions that may have been introduced when squaring

x = 6/5

√ (15x+18) = √ (15 (6/5) + 18) = √36 = 6

5x = 5 (6/5) = 6

x = - 3/5

√ (15x+18) = √ (15 (-3/5) + 18) = √9 = 3

5x = 5 (-3/5) = - 3

The only solution is: x = 6/5