Solve this linear system by graphing. Check the solution. 3x+y=11 x-2y=6

Mathematics · Middle School · Sun Jan 24 2021

Answered on

Given the equations:

3x + y = 11
Can be written as,
y = 11 - 3x (1st equation)

x - 2y = 6 (2nd equation)

Solution:

In order to solve the systems of equation, we substitute the value of y from the first equation to the 2nd equation.

x - 2y = 6

x - 2(11 - 3x) = 6

x - 22 - 6x = 6

-5x - 22 = 6

Transpose -5x and 6 to the opposite sides of the equation, hence it must be taken to note that in transposing a number, the sign changes.

5x = -22 - 6

5x = -28

Divide both sides by 5 in order to determine the value of x.

5x/5 = -28/5

x = -28/5

Substitute the value of x to the first equation and determine the value of y.

y = 11 - 3(-28/5)

y = 11 + 84/5

11 can be written as 55/5.

y = 55/5 + 84/5

y = 139/5

Final answer:

x = -28/5

y = 139/5