Question

Kuiz matematika

jika : a + b = 5ab
b + c = 7bc
c + a = 6ac
hitunglah nilai dari : a x b x c

peringatan : jangan ada spam ...

Answer 1

A+b = 5ab --> : ab
1/b + 1/a = 5

b+c = 7bc --> : (bc)
1/c + 1/b = 7

c+a = 6ac --> :(ac)
1/a + 1/c = 6

misal 1/a = x, 1/b = y dan 1/c = z
x + y = 5
y+ z = 7
x + z = 6
.
x+ y  =5
y+ z = 7
----------(-)
x - z = - 2
x+ z = 6
-----------(+)
2x = 4
x = 2 --> a = 1/2
z = 4 --> c = 1/4
x+y = 5
y = 3 --> b = 1/3

a .b. c = 1/24