Question #20bba

1 Answer
Nov 8, 2016

x=-1/2 and x=-3/2

Explanation:

Solve using the quadratic formula: 4x^2+8x=-3

To use the quadratic formula, the equation must be in the form
ax^2+bx+c=0

Add 3 to both sides to get all the terms on the left.

4x^2+8xcolor(white)(aaa)=-3
color(white)(aaaaaaa)+3color(white)(aaa)+3

color(red)4x^2+color(blue)8x+color(magenta)3=0

color(red)a=color(red)4, color(blue)b=color(blue)8, color(magenta)c=color(magenta)3

The quadratic formula is

x=frac{-color(blue)b+-sqrt(color(blue)b^2-4color(red)acolor(magenta)c)}{2color(red)a}

x=frac{-color(blue)8+-sqrt(color(blue)(8)^2-4(color(red)4)(color(magenta)3))}{2(color(red)4)}

x=frac{-8+-sqrt(64-48)}{8}

x=frac{-8+-sqrt(16)}{8}

x=(-8+-4)/8

Separate into two equations, one with a plus in the numerator and the other with a minus.

x=(-8+4)/8color(white)(aaaa)x=(-8-4)/8

x=(-4)/8color(white)(aaaaaaa)x=(-12)/8

x=-1/2color(white)(aaaaaaaa)x=-3/2