Hi,
I have a question in regard to a quadratic formula I'm solving.
4(a+b)±√(16(a²+2ab+b²)-48ab) / 24
4(a+b)±4√(a²-ab+b²) / 24
I don't understand how +2ab became -ab and why -48ab disappeared.
Anyone able to clarify that for me?
Thanks
David
Hi,
I have a question in regard to a quadratic formula I'm solving.
4(a+b)±√(16(a²+2ab+b²)-48ab) / 24
4(a+b)±4√(a²-ab+b²) / 24
I don't understand how +2ab became -ab and why -48ab disappeared.
Anyone able to clarify that for me?
Thanks
David
Hello Splint
Welcome to Math Help Forum!Just remove the inner brackets inside the square root and simplify:
$\displaystyle \sqrt{\Big(16(a^2+2ab+b^2)-48ab\Big)}$
$\displaystyle =\sqrt{(16a^2+32ab+16b^2-48ab)}$
$\displaystyle =\sqrt{16a^2 -16ab+16b^2}$
$\displaystyle =\sqrt{16}\sqrt{a^2-ab+b^2}$
$\displaystyle =4\sqrt{a^2-ab+b^2}$
Grandad