## anonymous 4 years ago Solve x2 + 8x – 48 = 0 by completing the square. Show your work for full credit.

For completing the square the coefficient of the "squared" term should be 1 and it is.

The term to be added to make it a perfect square is one half of the coefficent of the x term squared.

What you add you must also subtract to retain the equations original value.

4. anonymous

$(x^2+8x+16)-16-48$ <---- just added and substracted 4, which is $(8/2)^2$ Now try to factor out the term in brackets what do you get?

Lets see how saljudieh07 did this

Looks good.

7. anonymous

sorry $4^2$ that is what I added and substracted

8. anonymous

now, kaymarie12479 can you factor the expression in the brackets?

Actually you want to the square root of the value in the brackets. The origiinal equation is factorable, but you want to "complete the square. $(x + 4)^{2}=64$

$x+4=\pm8$

Note the original equation is factorable (x-4)(x+12)=0 however, they want you to use completing the square method.

Note. That factoring gives you x=4 and x=-12 as answer and x + 4 = +/- 8 gives same results x=4, and x=-12