Question

find the value of 9a²+16b ²,if 3a +3 = 9 and ab = 21​

Answer 1

Answer:

For example

Step-by-step explanation:

Given: 3a+4b = 16 ... (i) and ab = 4 ... (ii)

Squaring (i), we get

(3a+4b)2 = 162

9a2 + 16b2 + 24ab = 256

9a2 + 16b2 + 24 x 4 = 256 ... Using (ii)

9a2 + 16b2 = 256 - 96 = 160

Hence, 9a2 + 16b2 = 160.