Two regular octagons have areas of 48 mm² and x² + 8x mm². What values of x make the octagons congruent?

Question

stephstar101 · Answer

x^2+8x=48 <- set the two areas equal to each other
x^2+8x-48=0 <- subtract 48 from both sides
(x-4)(x+12)=0 <-factor them out
The last step is up to you! It'll give you the two final numbers, just solve for x!

ganpat · Answer

but the length cannot be negative.. So answer would be x= 4...

anonymous · Answer

my answers say 4 and 12 or 4 and -12

stephstar101 · Answer

It's not asking for the length, just the values of x that make them congruent :D So any number can be x

ganpat · Answer

@stephstar101 : hmmm, yes any value can  make it congruent.. @mr.perkins: so its 4 & -12..

ganpat · Answer

sorry, @mrs.perkins

anonymous · Answer

ok thank you