Question

Select all of the values that are solutions of x2 + 20 = 12x.

Answer 1

. x² + 20 = 12x  ⇔  x² -  12x  + 20 = 0
D = b  ²  - 4 a c = 64,
. x₁, ₂ = (- b ± √D  ) / ( 2a) = ( 12 ±√ 64) / 2 = ( 12 ± 8) / 2 ,
. x₁  = 10 , x  ₂  = 2

Answer 2

Answer:

2 and 10 are solutions of given expression  $x^2+20=12x$

Step-by-step explanation:

Given  expression $x^2+20=12x$    

We have to find the values that are solutions of given expression.

Since, the given expression is a quadratic equation , thus the roots are the  solutions of given expression.

Consider the given expression , $x^2+20=12x$

It can be written as ,$x^2-12x+20=0$

We can solve the given quadratic equation using middle term splitting method,

-12x can be written as -2x - 10x

$x^2-12x+20=0\\\\ x^2-2x-10x+20=0$

$x^2-12x+20=0$

taking x common from first two terms and -10 common from last two terms, we have,

$x(x-2)-10(x-2)=0$

$\Rightarrow (x-2)(x-10)=0$

using zero product property, we have,$ab=0 \Rightarrow a=0\ or\ b=0$

$\Rightarrow (x-2)=0$ or $\Rightarrow (x-10)=0$

$\Rightarrow x=2$ or $\Rightarrow x=10$

Thus, 2 and 10 are solutions of given expression  $x^2+20=12x$