Question

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X-7+2 (x-4)=-3x (×+2)-8

Answer 1

X-7+2 (x-4)=-3x (×+2)-8

x - 7 + 2x - 8 = - 3x^2 - 6x - 8

3x - 15 = - 3x^2 - 6x - 8

3x^2 + 6x + 3x - 15 + 8 = 0

3x^2 + 9x - 7 = 0

a = 3; b = 9; c = - 7

∆ = b^2-4ac

∆ = 9^2 - 4.3.(-7)

∆ = 81 + 12.7

∆ = 81 + 84

∆ = 165

x = [ - b +-/ √∆]/2a

x = [ - 9 +/- √165]/2.3

x = [ - 9 +/- √165]/6

x' = [ - 9/6 + √165/6]

x ' = - 3/2 + √165/6

x" = - 3/2 - √165/6