How do you solve the system of equations x-y=7 and

Shelia Lawrence 2021-12-25 Answered
How do you solve the system of equations xy=7 and 2x+5y=8 ?
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Expert Answer

Terry Ray
Answered 2021-12-26 Author has 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:
2x2y=14
Then we simply add that to the second equation:
2x2y=14
±2x+5y=8
3y=6
The positive 2x and the negative 2x cancel out, leaving us with just the 3y=6.
Divide both sides by 3 and we get y=2
Last, just plug 2 in for y in either equation (Ill
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Charles Benedict
Answered 2021-12-27 Author has 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
xy=7 and 2x+5y=8
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
2(xy=7)=2x2y=14 Add this to the second equation
2x+5y=8
+2x2y=14
3y=6
y=2
Now plug in the 2 for y in the first equation to solve for x
x2+2=7+2
x=9
We have now solved both variables. Check to make sure both equations are equal.
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karton
Answered 2021-12-30 Author has 368 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
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