Question 243359: Decide whether or not the ordered pair is a solution of the system.
(1, -3)
2x + y = -1
3x + 2y = -3
Answer by kamaldas(6)   (Show Source):
You can put this solution on YOUR website! Lets put the values of x and y from the ordered pair (1, -3) in the first equations:
2x + y = -1
or 2 (1) + (-3) =-1
or 2 -3=-1
or -1 =-1
True
Lets put the values of x and y from the ordered pair (1, -3) in the second equations:
3x + 2y = -3
or 3 (1) + 2(-3) =-3
or 3-6=-3
or -3=-3
True
As the ordered pair satisfies both the equations, it is a solution.
Alternative method
2x + y = -1 -------- Equation I
3x + 2y = -3 -------- Equation II
Multiply Equation I with 2, and we get
4x + 2y = -2 -------- Equation III
Subtract Equations III from Equation II
4x + 2y = -2
3x + 2y = -3
- - -
x =1
We get x=1
Put vakur of x=1 in any equation (say I)
2 +y=-1
y =-1 -2 =-3
Thus the solution set is (1,-3)
Contact me for online math tutorials and test prep for ACT/SAT/ GRE/GMAT /CLEP and others
|
|
|
