Question

Do the following: (a) Factorise by splitting the middle term: 84 - 2r - 2r2 (b) If a2 + b2 + c2 = 250 and a b + b c + c a = 3, find a + b + c

Answer 1

Answer:

(b) 16

Step-by-step explanation:

(b) Given- a²+b²+c²=250

ab+bc+ca=3

To find- value of a+b+c

solution:-

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

(a+b+c)²= 250+2×3

(a+b+c)²= 250+6

(a+b+c)²= 256

(a+b+c) = √256

∴ a+b+c = 16