Answer:
Step-by-step explanation:
(a - b)(a + b) =a² - b²
(3x + 5)(3x -5) =(3x)² - 5² = 9x² - 25
(x +2)(x+2) = (x+ 2)² = x²+ 2*2*x+2² = x² + 4x + 4
(x+2)(3x -5 ) = x*3x - 5*x +2*3x +2*(-5)
= 3x² -5x +6x -10
= 3x² + x - 10
13x² - 20x - 45 = 3*(3x² + x - 10)
13x² - 20x - 45 =9x² + 3x - 30
13x² - 9x² -20x - 3x - 45 + 30 = 0
4x² - 23x - 15 = 0