Question

How do you solve the system `3x/8-3y/5=33/80` and `4x/7+4y/5=37/35`?

Answer 1

Solution: `x = -24.38 , y= -17.3`

Explanation:

`3 x/8 - 3 y/5 =33/80 or 3+x/8 -(3+y/5)=33/80` or

`cancel3+x/8 -cancel3-y/5=33/80` multiplying by `80` on

both sides we get, `10 x -16 y=33 (1)`

`4 x/7 + 4 y/5 =37/35 or 4+x/7 +4+y/5=37/35` or

`8+x/7 +y/5=37/35` multiplying by `35` on

both sides we get, `280 +5 x +7 y=37 or 5 x +7 y= -243 (2)`

Multiplying equation (2) by `2` we get, `10 x +14 y= -486 (3)`

Subtracting equation (3) from equation (1) we get,

`-16 y- 14 y = 33 -(-486) or -30 y = 519 or y = -17.3`

Putting `y=-17.3` in equation (1) we get,

`10 x -16 *(-17.3)=33 or 10 x +276.8 =33` or

`10 x =33-276.8 or 10 x= -243.8 or x = -24.38`

Solution: `x = -24.38 , y= -17.3` [Ans]