Question

4x +5y =24
2x+7y=21​

Answer 1

x = 3.5, y = 2

Explanation:

This is a system of equations.

Original equations:

`4x+5y=24\\3x+7y=21`

Substitute y and solve for x:

→
`y=(24-4x)/(5) \\2x+7y=21`

Substitute the value for y and simplify:

→
`2x+(7(24-4x))/(5) =21`

→
`2x + ((168 - 28x))/(5)=21`

Multiply by 5 on both sides

→
`10x + 168-28x = 105`

Simplify →
`-18x = -63`

→
`x = 3.5`

Plug in the value for x into either equation:

→
`4*3.5 + 5y=24`

→
`14+5y=24`

→
`5y=10`

→
`y=2`

Answer 2

Use elimination
Multiply second equation by 2
4x + 14y = 42
4x + 5y = 24
Now subtract both
9y = 18
Y = 2
Plug 2 into equation to solve for x
4x + 5(2) = 24
4x = 14
x = 3.5, y = 2