Question

please answer this and you will get 90+ pts on this correct answer any one of these sums

Answer 1

a²+b²+c²=250
ab+bc+ca=3
a²+b²+c²+2(ab+bc+ca)=(a+b+c)²
(a+b+c)²=250+2*3
(a+b+c)²=256
a+b+c=√256=16

Answer 2

Solution 9.)

ab + bc + ca = 20 ---------(1)

a + b + c = 7

On squaring both sides, we get

a^2 +b^2 + c^2 + 2(ab + bc + ca) = 49

=> a^2 +b^2 + c^2 + 2 (20) = 49 [ using equation 1]

=> a^2 +b^2 + c^2 + 40 = 49

=> a^2 +b^2 + c^2 = 9
________________________

Solution 11.)

ab + bc + ca = 3 -------(1)

a^2 +b^2 + c^2 = 250 ------(2)

Now,

(a+b+c)^2 = a^2 +b^2 + c^2 + 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) = 16