Question

If a+b=7 and ab =12,find the value of apower4 minus bpower4​

Answer 1

Answer:

Given, a+b =7, ab = 12

Therefore

ab =12

a=12/b

12/b + b = 7

12+b²=7b

b²-7b+12=0

b²-3b-4b+12=0

b(b-3) -4(b-3) =0

(b-4) (b-3) =0

b=4 or b =3

so, a is 3 or 4

So, a⁴-b⁴=(taking b=3) 81-256 =-175

taking b=4

256-81=+175