How do you solve x(2x + 7) = 4?

2 Answers
Apr 23, 2016

x=-4and x=1/2

Explanation:

=>2x^2+7x-4=0
=>2x^2+8x-x-4=0
=>2x(x+4)-1(x+4)=0
=>(x+4)(2x-1)=0
x=-4and x=1/2

Apr 23, 2016

x = -4
OR
x = -0.5

Explanation:

x(2x + 7) = 4
First multiply out the brackets and bring the 4 to the left hand side
2x^2 + 7x - 4 = 0
Then plug the above equation into the quadratic formula where
a = 2 b=7 and c= -4
(-7 ± sqrt(49 - (4 * 2 * -4))/ 4)

This will give you two answers using the +/- before the square root for 2 different answers.