Question

3(6x-6)+2x²=x²+11x-28

Answer 1

3 (6x - 6) + 2 x² = x² + 11x - 28
18x - 18 + 2x² = x² + 11x - 28
18x - 18 + 2x² - x² - 11x + 28 = 0
2x² - x² + 18x - 11x - 18 + 28 = 0
x² + 7x + 10 = 0

x = - b +/- √Δ
          2a

Δ = b² - 4ac = 49 - 4.(1.10)
Δ = 9

x = - 7 +/- √9
         2

 x¹ = - 7 + 3 = - 4 = - 2    
             2        2

x¹¹ = - 7 - 3 = - 12 = - 5     
            2         2

x' = - 2
x'' = - 5