Question

I need help with this

Answer 1

Option B

Option C

Explanation:

`x^(2) +2x=4`

we need to divide the coefficient of x by half since it is required for completing square, this term is added and subtracted at the same time to keep the equation intact, so we have

`x^(2) +2x+1-1=4`

later we have

`(x+1)^(2) -1=4`

`(x+1)^(2)= 4+1`

`(x+1)^(2) = 5`

`\sqrt{(x+1)^(2)} =√(5)`

we know

`\sqrt[2]{a^(2)} = abs (a)`

`abs(x+1)=√(5)`

we have

`x+1=√(5)`

or

`x+1= -√(5)`

so we have

`x=√(5)-1`

`x=-√(5)-1`

finally

`x=+- √(5)-1`

The second is obtained by summing the two given equations

f(x)=8x-10

g(x)=3x+5

-----------------

f(x)+g(x)=11x-5