Question

If a+b=7 and ab=4 find a^2+b^2 and a^3+b^3

Answer 1

Step-by-step explanation:

a+b=7

ab= 4

To find:-

a²+b²

and a³+b³

1.) a²+b²

the formula to find (a+b)² is

(a+b)²=a²+b²+2ab

by this formula, we can find a²+b²

a²+b²=(a+b)²-2ab

( a+b=7 and ab=4 )

a²+b²=7²- 2×4

a²+b²=49-8

a²+b²=41

2.) a³+b³

(a+b)(a²+b²-2ab)

(7)(41- 2 × 4)

7 × 33

231

a³+b³=231

hope it helps