Question

Solve the system using subtraction. 7x + 2y = 13 –x + 2y = –11 What is the solution of the system?

Answer 1

Answer:

$x=3\\y=-4$

Step-by-step explanation:

Subtract both equations:

$(7x+2y)-(-x+2y)=13-(-11)$

Distribute the negative signs and then you need to add the like terms:

$7x+2y+x-2y=13+11\\8x=24$

 BY the division prperty of equality, divide both sides of the equation by 8:

$\frac{8x}{8}=\frac{24}{8}\\x=3$

Substitute the value of x obtained into any of the original equations to find the value of y. Then you get:

$7x+2y=13\\7(3)+2y=13\\21+2y=13\\2y=-8\\y=-4$

Answer 2

ANSWER

The solution is

x=3, y=-4

EXPLANATION

We were given two equations in two variables.

First equation:

$7x + 2y = 13$

Second equation:

$- x + 2y = - 11$

Subtract the second equation from the first equation:

$(7x - - x) + (2y - 2y) = 13 - - 11$

This gives us,

$7x + x + 0= 13 + 11$

$8x= 24$

Divide both sides by 8.

$x = \frac{24}{8}$

$x = 3$

Put x=3 into the first equation:

$7(3) + 2y = 13$

$21 + 2y = 13$

Group similar terms;

$2y = 13 - 21$

$2y = - 8$

Divide both sides by 2,

$y = \frac{ - 8}{2} = - 4$

The solution is

x=3, y=-4