Question

find a+b+c.if a²+b²+c² =100 ab+bc+ ca =28​

Answer 1

Answer:

12.49

Step-by-step explanation:

We know

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

$(a+b+c)^{2}=100+2*28=156$

$a+b+c=\sqrt{156}=12.49(approx)$

Have a nice day!!

Answer 2

Step-by-step explanation:

Here,

a²+b²+c² =100 and, ab+bc+ ca =28

Then,

(a+b+c)²= a²+b²+c²+2ab+2bc+2ca

= (a²+b²+c²) + 2(ab+bc+ca)

= 100 + 2×28

= 100 + 56

or, (a+b+c) ² = 156

i.e. (a+b+c) = √156