Question

What is the positve solution for this equation? 4x2 + 12 x= 135

Answer 1

We need to solve the following equation for x, and choose the positive solution

`4x^2+12x=135`

we substract 135 from both sides of the equation obtaining the canonical form of a quadratic equation, the we apply the quadratic formula with a=4, b=12 and c=-135 then x will be equal to:

`x=\frac{-12+\sqrt[]{144-4(4)(-135)}}{8}=(48-12)/(8)=(9)/(2)=4.5`

then the positive solution to the equation will be x=4.5