## Trending News

Promoted

### 1 Answer

Rating

- 1 decade agoFavorite Answer
X÷3+Y÷5=2

X÷5+Y÷3=-2

2條都乘15, 變成

5x + 3y = 30

3x + 5y= -30

5同3的lcm係15

上面eqn 乘3

下面eqn乘5

15x + 9y= 90

15x + 25y = -150

上面eqn減下面eqn

-16y = 240

y = -15

代入 X÷3+Y÷5=2

x/3 + (-15/5) = 2

x/3-3 = 2

x/3 = 5

x = 15

Source(s): maths tutor

Still have questions? Get your answers by asking now.