Question

20. Find the solution to the system of linear equations below:

x - 3y = -5
2x + 5y = 12
O (-5, 12)
O (3,2)
O (-2,7)
O (1,2)

Answer 1

(1, 2)

Explanation:

So you can solve this systems of equations by substitution. Substitution involves "finding" the value of one of the variables and then substituting that into the other equation

In this example I'll try to define an equation equal to that of "2x" using the first equation and then substitute that into the second equation

Given:

`x-3y=-5`

Add 3y to both sides

`x=3y-5`

Multiply both sides by 2

`2x = 6y-10`

Given:

`2x+5y=12`

Substitute 2x as (6y-10)

`(6y-10)+5y=12`

Simplify

`11y-10=12`

Add 10 to both sides

`11y = 22`

Divide both sides by 11

`y=2`

Plug 2 in as y (works for either given equation)

`x-3(2)=-5`

simplify

`x-6=-5`

add 6 to both sieds

x=1