Question

URGENT

(i) If a+b+c =9 and ab+bc+ ca 26,find
${a}^{2} + {b}^{2} + {c}^{2}$
(ii) Expand by using suitable identity: (4-1/3x)'


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Answer 1

1.(a+b+c)²= a²+b²+c²+2(ab+bc+ca)

9² = a²+b²+c²+2*(26)

81= a²+b²+c²+52

81-52 = a²+b²+c²

29 = a²+b²+c²

So, a²+b²+c²= 29

Hope it helps you