Question

If a+b =9 and ab =5 , find the value of a square +b square ​

Answer 1

Answer:

a²+b²=71

Step-by-step explanation:

Given a+b=9 ---(1)

ab = 5 ---(2)

On Squaring equation (1) , we get

(a+b)² = 9²

=> a²+b²+2ab=81

=> a²+b²+2×5=81 /*From (1)

=> a²+b²+10= 81

=> a²+b² = 81-10

=> a²+b² = 71

Therefore,

a²+b² = 71

Answer 2

Answer:

a

$a { }^{2} + b {}^{2} = 71$

Step-by-step explanation:

Given a+b=9

By squaring both sides

(a+b)2=81

By expanding

$a {}^{2} + 2ab + b {}^{2} = 81$

Give ab=5

2ab=10

Hence answer 81-10=71