Question

고
2
If a+b=7 and ab=12
find 3 (a²+ab +b²)​

Answer 1

Answer:

(a+b)²=a²+2ab+b²=7²=49

a²+2ab+b²-ab= (a²+ab +b²) =49-12 =37

3 (a²+ab +b²)= 3×37= 111

Answer 2

Answer:

$(a+b) = 7\\ab = 12$

=> $(a +b)^2=7^2$

=> $(a ^2 + b^2 + 2ab) = 49$

=> $a^2 + b^2 + 2(12) = 49$

=> $a^2 + b^2 + 24 = 49$

=> $a^2 + b^2 = 25 ---------- Eq. 1$

$Putting$ $Given$ $Values$ $of$( $a^2 + b^2$ & $ab$ ) $as$ ( $25$ $and$ $12$ )

$3(a^2+ab+b^2)$

=> $3((a^2 + b^2) + (ab))$

=> $3 ( 25 + 12 )$

=> $3 * 37$

=> $111$