Respuesta :
I will help you do it the correct way.
To solve by substitution, you must cancel out either x or y.
We will choose x, as -x and 2x are easier to change and cancel.
We multiply the second equation by 2 to make -x -2x, the opposite of 2x in the first equation.
y=-x+34
2(y = -x + 34)
2y = -2x + 78
We add the equations together.
y = = 2x - 20
2y = -2x + 68
y + 2y = 2x - 2x + 68 - 20
Combine like terms
3y = 48
isolate y
3y = 48
/3 /3
y = 16
Now we substitute 16 in for y in an original equation.
Let's choose the first equation.
Y=2x-20
16 = 2x - 20
Isolate x
16 = 2x - 20
+20 +20
36 = 2x
/2 /2
18 = x
x = 18
y = 16
The solution is (18, 16)
To check, substitute both into both equations and see whether or not the equation is true. (you can surely do this on your own)
To solve by substitution, you must cancel out either x or y.
We will choose x, as -x and 2x are easier to change and cancel.
We multiply the second equation by 2 to make -x -2x, the opposite of 2x in the first equation.
y=-x+34
2(y = -x + 34)
2y = -2x + 78
We add the equations together.
y = = 2x - 20
2y = -2x + 68
y + 2y = 2x - 2x + 68 - 20
Combine like terms
3y = 48
isolate y
3y = 48
/3 /3
y = 16
Now we substitute 16 in for y in an original equation.
Let's choose the first equation.
Y=2x-20
16 = 2x - 20
Isolate x
16 = 2x - 20
+20 +20
36 = 2x
/2 /2
18 = x
x = 18
y = 16
The solution is (18, 16)
To check, substitute both into both equations and see whether or not the equation is true. (you can surely do this on your own)
