Question

If (3a+4b)= 16 and ab=4, find the value of (9a×a+16b×b)

Answer 1

Answer:160

Step-by-step explanation:

Consider

(3a +4b)²=9a²+16b²+2×3×4×ab

Now we know 3a +4b is 16 and ab is 4

So

16²=9a²+16b²+24×4

256-96=9a²+16b²

Which is 160