Question

Factor the expression.
2x2 + x - 15

Answer 1

`2x^2 + x - 15 =0\\ \\a=2 , \ b = 1 , \ c= -15 \\ \\\Delta = b^(2)-4ac = 1^(2)-4*2* (-15)=1 +120 = 121 \\ \\x_(1)=(-b-√(\Delta ))/(2a) =(-1-√(121))/( 2*2)=(-1-11)/(4)=(-12 )/(4 )= -3\\ \\ x_(2)=(-b+√(\Delta ))/(2a) =(-1+√(121))/( 2*2)=(-1+11)/(4)=(10)/(4 )= (5)/(2) \\ \\ \\ Answer : \ 2x^2 + x-15 = (x+3)(x-(5)/(2))`