Question

a+b+c=9,ab+bc+ac=40 find a²+b²+c²

Answer 1

Hi...☺

Here is your answer...✌
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a+b+c = 9

ab+bc+ac = 40

We know that,

(a+b+c)² = a²+b²+c²+2ab+2bc+2ac

a²+b²+c² = (a+b+c)²-2(ab+bc+ac)

a²+b²+c²+2 = (9)²-2(40)

a²+b²+c² = 81-80

a²+b²+c² = 1

Answer 2

Hi ,


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

ab + bc + ca = 40

2( ab + bc + can ) = 80 ---( 2 )

a² + b² + c² + 2ab + 2bc + 2ca = ( a + b + c )²

a² + b² +c² = (a + b + c)² - 2(ab+bc+ca)

= 9² - 80

= 81 - 80

= 1

I hope this helps you.

: )