If 2a + 3b = 8 and ab = 5. then find the value of $4a^2 + 9b^2$.
Answer & explanation
Correct answer: option 2
We know that,
( a + b )2 = a2 + b2 + 2ab
If 2a + 3b = 8
ab = 5.
then find the value of $4a^2 + 9b^2$ = ?
( 2a + 3b )2 = 4a2 + 9b2 + 2(6)(5)
= 4a2 + 9b2 = 64 - 60
4a2 + 9b2 = 4