If a−b=3 and ab=10; find a3−b3
a−b=3⇒(a−b)3=(3)3⇒a3−b3−3ab(a−b)=27⇒a3−b3−3×10(3)=27⇒a3−b3−90=27⇒a3−b3=27+90⇒a3−b3=117.
If a + b = 10 and ab = 21, find the value of a3+b3.