Question

6a^3-6b^3
---------------- =
3a^2 -3b^2

a=6,5; b=2,5

Answer 1

$dfrac{6a^3-6b^3}{3a^2-3b^2}= dfrac{6(a-b)(a^2+ab+b^2)}{3(a+b)(a-b)}= dfrac{2a^2+2ab+2b^2}{3a+3b}$
если а=6,5 а b=2,5, то
$dfrac{2*6,5^2+2*6,5*2,5+2*2,5^2}{3*6,5+3*2,5}=dfrac{84,5+32,5+12,5}{19,5+7,5}=dfrac{129,5}{27}=\=dfrac{1295}{270}=4dfrac{215}{270}$