Question

Solve the system of equations by substitution. 3/8 x + 1/3 y =17/24 and
x + 7y = 8

Answer 1

1,1

Explanation:

Correct:)

Answer 2

`\left \{ {{ (3)/(8)x+ (1)/(3)y = (17)/(14) } \atop {x+7y=8}} \right.`

To solve this system by substitution, first isolate x in the second equation.


`x+7y=8`

`x+7y-7y=8-7y`

`x=8-7y`

Now, plug this expression (
`8-7y`) for x in the top equation to solve for y.


`(3)/(8) (8-7y)+ (1)/(3) y= (17)/(14)`

`3- (21)/(8) y+ (1)/(3) y= (17)/(24)`

`72-63y+8y=17`

`72-55y=17`

`-55y=17-72`

`-55y=-55`

`y=1`

Now that you have y, plug it into the second equation and solve for x.


`x+7y=8`

`x+7(1)=8`

`x+7=8`

`x=1`

Last step is to plug your x- and y-values in to both equations to check your work.


`(3)/(8) (1)+ (1)/(3) y= (17)/(24)`


`(3)/(8) * (3)/(3) = (9)/(24) ; (1)/(3) * (8)/(8) = (8)/(24)`


`(9)/(24) + (8)/(24) = (17)/(24)` <--True


`1+7(1)=8`

`1+7=8` <--True

Answer:

`x=1 \\ y=1`