jika a+b=5ab, b+c = 7bc, dan c+a =6ac,nilai dari a×b×c adalah ...

a + b = 5ab ---> a = 5ab - b
b + c = 7bc ---> b = 7 bc - c
c + a = 6ac ----> c = 6ac - c

a x b x c =
(5ab - b) x (7bc - c ) x ( 6ac - a ) =
210 a^2b^2c^2 + 5a^2bc -42ab^2c^2 - abc