Question

Quadratic equations and complex numbers PPEASE ANSWER ASAP

Answer 1

When you solve the following equation, solving for the quadratic formula.

The answer is; x=4

Next time pay attention in class.

Answer 2

12.
`x=-3(1)/(2), x = 6`

15.
`4`

Explanation:

12.
`2x^2-5x=42`

To solve this quadratic equation, we will put all the variables and constants on one side of the equation and factorize it.

`2x^2-5x-42=0`

`2x^2-12x+7x-42=0`

`2x(x-6)+7(x-6)=0`

`(2x+7)(x-6)=0`

`x=-(7)/(2), x = 6`

`x=-3(1)/(2), x = 6`

Therefore, the solutions to the given expression are 3(1/2) and 6.

15.
`3x=8+√(3x+4)`

`3x-8=√(3x+4)`

Squaring both the sides to get:

`(3x-8)^2=(3x+4)^2`

`9x^2-48x+64=3x+4`

`9x^2-51x+60=0`

`3(3x^2-17x+20)=0`

`3x^2-17x+20=0`

`3x^2-12x-5x+20=0`

`3x(x-4)-5(x-4)=0`

`x=(3)/(5) (ignore), x=4`

Therefore, the solution to the given expression is 4.