Question

Cara no.1 , bagaimana ya? mohon bantuan :")

Answer 1

Dik:
a²+2b = 7
b²+4c = -7
c²+6a = -14
dit: a²+b²+c² = ......?
jawab:
a²+b²+c²+2b+4c+6a = 7 - 7 - 14
a²+b²+c²+2b+4c+6a = -14
a²+b²+c²+2b+4c+6a-14 = 0
(a²+6a+9)+(b²+2b+1)²+(c²+4c+4) = 0
(a+3)² + (b+1)² + (c+2)² = 0
sehingga:
(a+3)² = 0
a+3 = 0
a = -3

(b+1)² = 0
b+1 = 0
b = -1

(c+2)² = 0
c+2 = 0
c = -2
maka:
a²+b²+c² = (-3)² + (-1)² + (-2)²
              = 9 + 1 + 4
              = 14