Question

I need help with this

Answer 1

Answer:

Option B

Option C

Step-by-step 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

$(x+1)^{2} -1=4$

$(x+1)^{2}= 4+1$

$(x+1)^{2} = 5$

$\sqrt{(x+1)^{2}} =\sqrt{5}$

we know

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

$abs(x+1)=\sqrt{5}$

we have

$x+1=\sqrt{5}$

or

$x+1= -\sqrt{5}$

so we have

$x=\sqrt{5}-1$

$x=-\sqrt{5}-1$

finally

$x=+- \sqrt{5}-1$

The second is obtained by summing the two given equations

f(x)=8x-10

g(x)=3x+5

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

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