How do you solve the system of equations x-y=7 and
Shelia Lawrence
Answered question
2021-12-25
How do you solve the system of equations and ?
Answer & Explanation
Terry Ray
Beginner2021-12-26Added 50 answers
Your goal here is to remove one of the variables from the problem. You can see that the first equation has x and the second equation has -2x. If we double the first equation, we get:
Then we simply add that to the second equation:
The positive 2x and the negative 2x cancel out, leaving us with just the .
Divide both sides by 3 and we get
Last, just plug 2 in for y in either equation (Ill
Charles Benedict
Beginner2021-12-27Added 32 answers
Begin by solving either the x or y variable by first eliminating or canceling out one of the variables. We can then plug in that variable into the first equation and solve for the second equation
and
To Solve for y in the second equation, start by multiplying the first equation by 2 and add the result to second in order to cancel out the
Add this to the second equation
Now plug in the 2 for y in the first equation to solve for x
We have now solved both variables. Check to make sure both equations are equal.
karton
Expert2021-12-30Added 613 answers
Solve system of equations:
These are linear equations. Since they are a system, both equations are solved simultaneously by substitution. The resulting values for x and y is the point at which the two lines intersect on a graph.
The two equations are:
x-y=7 and -2x+5y=-8
First Equation: x-y=7
x-y=7
Add y to both sides.
x=7+y
Second Equation: -2x+5y=-8
Substitute 7+yfor x in equation.
-2(7+y)+5y=-8
Simplify.
-14-2y+5y=-8
Add 14 to both sides.
2y+5y=-8+14
Simplify.
3y=6
Divide both sides by 3.
y=2
Now substitute the value of y back into the firs equation and solve for x.
x-2=7
Add 2 to both sides.
x=9