Question 107324: solve the following sytems of equations
1. 2. 3.
y=7x-8 6x+7y=19 3x-2y=4
y=3x-12 x+y=5 2x+y=12 Answer by elima(1433) (Show Source):
You can put this solution on YOUR website! Since it doesn't say which method to use, I will use the substitution method;
1)y=7x-8
y=3x-12
Lets substitute y=3x-12 for y in the other equation
(3x-12)=7x-8
3x-7x=-8+12
-4x=4
x=-1
Now plug that in for x in either equation;
y=7(-1)-8
y=-7-8
y=-15
========================================
2)6x+7y=19
x+y=5
------------------------
for this one lets solve the second equation for x and then use that answer in the first equation;
x=5-y
6(5-y)+7y=19
30-6y+7y=19
y=19-30
y=-11
x-11=5
x=5+11
x=16
=====================================
3)3x-2y=4
2x+y=12
--------------------
lets solve the second equation for y;
y=12-2x
-----------------------------
3x-2(12-2x)=4
3x-24+4x=4
7x=4+24
7x=28
x=4
2(4)+y=12
8+y=12
y=12-8
y=4
:)
(