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

1 Answer

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