Question

Part 1:
Solve the following system of equations. Please show your work to receive full credit.
x - y = 19
2x + y = 2

Part 2:
Explain which method you chose to solve the system and why you felt it was the best choice.

Answer 1

I'm so confused

Answer 2

ok.... so looking at the 2 equations..... the easiest letter to eliminate is y. they have opposite sides...

x - y = 19 adding the 2 equations will eliminate y and allow you to
2x + y = 2 solve for x
-----------
3x = 21

now divide both sides of the equation to find x.

x = 7

to find the value of y, substitute x = 7 into either original equation

I'll choose the 1st equation

7 - y = 19 subtract 7 from both sides of the equation

-y = 12 divide by -1 to get the value of y

y = -12

so the solution to these 2 equations is x = 7 and y = -12

All the solution means that if you graphed these to lines on the number planes
you would see they intersect at (7, -12)

hope that makes sense.

Answer 3

other methods you can use to solve these equations are

1. graphing... but given the solution (7, -12) you would need a large number plane.

2. Substitution method.

which means taking an equation, changing the subject and then substituting into the other equation.

If I choose the 1st equation and make x the subject you get

x = y + 19

now substitute it into the 2nd equation

2(y + 19) + y = 2

distributing

2y + 38 + y = 2

collect like terms

3y + 38 = 2

and if you continue you'll find

y = -12... same as before... and substituting you would get x = 7


For this question elimination is the easier method because the y terms have the same coefficient and opposite signs... so adding them well cause them to be eliminated.

Hope it all makes sense

Answer 4

Thx much better

Answer 5

glad to help