Question

How do you solve `x(x-4)-2=43`?

Answer 1

`x_"1"=-5`, `x_"2"=9`

Explanation:

`x(x-4)-2=43`
`x*x-x*4-2=43`
`x²-4x-2-43=43-43`
`x²-4x-45=0`
`Δ=(-4)²-4*1*(-45)`
`Δ=196`
`x=(-b+-sqrt(Δ))/(2a)`
`x_"1"=(-(-4)-sqrt(196))/2`
`x_"2"=(-(-4)+sqrt(196))/2`
`x_"1"=-5`, `x_"2"=9`
\0/ here's our answer!

Answer 2

`x=`9 or -5

Explanation:

Expand the bracket

`x(x-4)-2=43` `=>` `x^2-4x-2=43`

Subtract 43 from both sides

`x^2-4x-45=0`

Factorise

`(x-9)(x +5)=0`

So `x=9 or -5`