Question

How do you solve the following system of equations?: #10x – 30y = -1, 2x + y = 8 #?

Answer 1

`x=239/70`
`y=41/35`

Explanation:

From the given:

`10x-30y=-1" "`first equation
`2x+y=8" "`second equation

Solve by method of substitution:
Start with the second equation

`y=8-2x`
Use this in the first equation

`10x-30y=-1" "`first equation
#10x-30(8-2x)=-1

`10x-240+60x=-1`

`70x=239`

`x=239/70`

Now use this value to solve y:
Go back to `y=8-2x`

`y=8-2(239/70)`

`y=(560-478)/70`

`y=82/70`

`y=41/35`

checking
`10x-30y=-1" "`first equation
`10(239/70)-30(41/35)=-1`

`239/7-246/7=-1`

`-7/7=-1`
`-1=-1`

checking:
`2x+y=8" "`second equation

`2(239/70)+41/35=8`

`239/35+41/35=8`
`280/35=8`

`8=8`

God bless....I hope the explanation is useful