Question

Can someone help me solve this

(x+2)^2 = 11^2+4^2

I want to solve it by expanding the (x+2)^2

Answer 1

so, can you expand (x+2)^2 ?

Answer 2

yes it becomes
x^2+4x+4

Answer 3

x^2+4x+4 = 11^2+4^2
whats 11^2+4^2 =... ?

Answer 4

137

Answer 5

x^2+4x = 133

Answer 6

but what now from here ?

Answer 7

x^2 +4x -133 =0
do you know how to solve quadratic equations ?

Answer 8

no

Answer 9

Compare your quadratic equation with \(ax^2+bx+c=0\)
find \[a=...?\\b=...?\\c=...?\]
then the two roots of x are:
\(\huge{x_{1,2}=\frac{-b \pm \sqrt{b^2-4ac}}{2a}}\)

Answer 10

Thanks,

Answer 11

ok, welcome :)
you can ask if you get stuck while getting the values of x