Expert: Scott A Wilson - 11/29/2011

Question
were learning about solving quadratic equations in my class right now and I'm stuck on a homework question: 2(x-3)^2=8. The directions say "solve the equation"

Answer
Divide both sides of the equation by 2.  This gives (x-3)² = 4.
Take the squareroot of both sides.  The sqrt(4) = 2 or -2, so this gives x-3 = 2 or x-3 = -2.
Add 3 to both sides of both equations.  This gives x = 5 or x = 1.

Put x = 1 and x = 5 back in the original to check.
This gives 2(1-3)^2 = 8 or 2(5-3)^2 = 8.
For the 1st one, 1-3=-2, and (-2)^2 = 4, and 2*4 = 8, so that checks out.
For the 2nd one, 5-3=2, and 2^2 = 4, and 2*4 = 8, so that checks out as well.