Question

solve -81+4x^2=0 by factoring

Answer 1

Remember the rule about factoring differences of squares: \(a^2-b^2 = (a+b)(a-b)\). Does that help you out?

Answer 2

no can u explain it farther

Answer 3

So are the two parts of the equation (\(81\) and \(4x^2\)) squares?

Answer 4

ok

Answer 5

Now set \(a=4x^2\) and \(b=81\), and plug it in to the equation I gave above.

Answer 6

Uh... correction: \(a^2 = 4x^2\) and \(b^2 = 81\).

Answer 7

Yep. (2x - 9) (2x + 9)

Answer 8

\[-81+4x^2=0\]

Answer 9

can u explain step by step because i am on these problems in my math class