Sagot :
[tex]2x + 4y = 16\\
x - 7 = 4y\\\\
2x + 4y = 16\\
x = 4y+7\\\\
2(4y+7)+4y=16\\
8y+14+4y=16\\
12y=2\\
y=\frac{2}{12}=\frac{1}{6}\\\\
x=4\cdot\frac{1}{6}+7\\
x=\frac{4}{6}+7\\
x=\frac{2}{3}+\frac{21}{3}\\
x=\frac{23}{3}[/tex]
Ugh why do you even have to use substitution method, the elimination method is so much easier in this instance... :/
Okay well first off you want to get x alone on one side of the equals sign.
x - 7 = -4y
+ 7 + 7
---------------
x = -4y + 7
Then you plugin -4y + 7 for x in the other equation.
2(-4y + 7) + 4y = 16
Then distribute.
-8y + 14 + 4y = 16
Combine like terms.
-4y + 14 = 16
-14 -14
-----------------------
-4y = 2
---- ------
-4 -4
y = -0.5
x - 7 = -4(-0.5)
-----------------------
x - 7 = 2
+ 7 +7
----------------
x = 9
Then you plugin the answers for each variable to check, but I will let you do that.
Okay well first off you want to get x alone on one side of the equals sign.
x - 7 = -4y
+ 7 + 7
---------------
x = -4y + 7
Then you plugin -4y + 7 for x in the other equation.
2(-4y + 7) + 4y = 16
Then distribute.
-8y + 14 + 4y = 16
Combine like terms.
-4y + 14 = 16
-14 -14
-----------------------
-4y = 2
---- ------
-4 -4
y = -0.5
x - 7 = -4(-0.5)
-----------------------
x - 7 = 2
+ 7 +7
----------------
x = 9
Then you plugin the answers for each variable to check, but I will let you do that.