This is really tripping me up, I have to find the root of 3X^2 + 5X = 0

Question

This is really tripping me up, I have to find the root of 3X^2 + 5X = 0

Answer 1

Hello Kristine,

Its a quadratic equation, therefore it'll have 2 roots. Here's step by step to find the roots of the equation.

• Take out x common from both the terms using distributive property ( ab + ac = a(b + c))

3x² + 5x = 0

x(3x + 5) = 0

• either x has to be 0 or (3x + 5) has to be 0 to make the entire equation equal to 0.
• set x = 0 or (3x + 5) = 0
• solve for x. Roots will be

x = 0 and 3x + 5 = 0

               3x + 5 -5 = -5 (subtract 5 from both sides)

               3x = -5

                (3/3)x = (-5/3)  (divide both sides by 3)

                x = -5/3

Therefore roots of the quadratic equation 3x² + 5x = 0 are

x = 0 and x = -5/3 (answer)

I hope this helps.

 

Answer 2

Hi Kristine,

First, we need to factor this equation: 3x² +5x = 0 = x(3x +5) = 0 in factored form.

Next, remember the only way to multiply two numbers and get a result of 0 is if one or both of them = 0 so we set both terms being multiplied equal to zero, 

x= 0 and 3x + 5 = 0. Finally we solve any unsolved equations for x and we have our answers:

x = 0 (already solved) and 3x = -5

                                       x = -5/3. So our roots are 0 and -5/3.

Answer 3

1. Factor the equation first.

2. Then you will see x=0 or 3x+5=0

3. You will find this equation has 2 roots!