Question

Use the quadratic formula to solve the equation 2x^2+2x-4=0

Answer 1

x = -2 or x = 1

Explanation:

The quadratic formula for the quadratic equation ax² + bx + c = 0:

`x=(-b\pm√(b^2-4ac))/(2a)`

`2x^2+2x-4=0\qquad\text{divide both sides by 2}\\\\x^2+x-2=0`

`a=1,\ b=1,\ c=-2`

Substitute:

`x=(-1\pm√(1^2-4(1)(-2)))/(2(1))=(-1\pm√(9))/(2)=(-1\pm3)/(2)\\\\x_1=(-1-3)/(2)=(-4)/(2)=-2\\\\x_2=(-1+3)/(2)=(2)/(2)=1`