SOLUTION: Solve the system by graphing.4x + 2y = 10 Solve the system by substitution. 3x – y = –7 x + y = –9

Algebra ->  Expressions-with-variables -> SOLUTION: Solve the system by graphing.4x + 2y = 10 Solve the system by substitution. 3x – y = –7 x + y = –9       Log On


   

Question 113959:

Solve the system by graphing.4x + 2y = 10
Solve the system by substitution. 3x – y = –7
x + y = –9

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
4X+2Y=10
2Y=-4X+10
Y=-4X/2+10/2
Y=-2X+5
+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+y+=+-2x+%2B5%29+ (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, y = -2x +5).
----------------------------------------------------------------------
3X-Y=-7
X+Y=-9
----------- NOW ADD.
4X=-16
X=16/-4
X=-4 ANSWER.
3*-4-Y=-7
-12-Y=-7
-Y=-7+12
-Y=5
Y=-5 ANSWER.
PROOF
-4+(-5)=-9
-4-5=-9
-9=-9