Question

Q3. If ab+bc+ca=71 and a+b+c=15, then the value of a+ba+c2 is equal to:​

Answer 1

Answer:

Given:-

ab+bc+ca= 71

a+b+c= 15

to find:-

a^2+b^2+c^2

Solution:-

(a+b+c)^2= a^2+b^2+c^2+2(ab+bc+ca)

(15)^2= a^2+b^2+c^2+2(71)

225= a^2+b^2+c^2+147

a^2+b^2+c^2= 225-147

=78

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Answer 2

hay!!

question

$if \: a + b + c = 15 \: and \: ab + bc + ca = 71 \: then \: find \: the \: value \: of \: a {}^{2} b {}^{2} c {}^{2}$

given

a + b + c = 15

ab + bc + ca = 71

to find

$a {}^{2}+ b {}^{2}+ c {}^{2}$

answer

083

formulas used

$a {}^{2}+ b {}^{2} +c {}^{2}=a {}^{2}+ b {}^{2} +c {}^{2}+2(ab+bc+ca)$

${\sf{\red{\underline{\Large{Explanation}}}}}$

formula

=>(a+b+c)²=a²+b²+c²+2(ab + bc + ac)

putting the values

=>(a+b+c)²=a²+b²+c²+2(ab + bc + ac)

=>(15)²=a²+b²+c²+2(71)

=>225 =a²+b²+c²+142

=>225-142=a²+b²+c²

=>083. answer.

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