2x-3y=7;5x+y=9
In substitution method
Answers
Answer:
x=2
y=-1
Step-by-step explanation:
2x-3y=7=>(1)
5x+y=9=>(2)
(1)=> 2x-3y=7
(2)*3=> 15x+3y=27
__________
17x=34
x=2
In (1)=>2(2)-3y=7
-3y=7-4
-3y=3
y=-1
Solution:
Given Equation:
=> 2x - 3y = 7
=> 5x + y = 9
By Substitution Method:
=> 2x - 3y = 7 .............(1)
=> 5x + y = 9 .............(2)
=> y = 9 - 5x
Put the value of y in equation (1), we get
=> 2x - 3y = 7
=> 2x - 3(9 - 5x) = 7
=> 2x - 27 + 15x = 7
=> -27 + 17x = 7
=> 17x = 7 + 27
=> 17x = 34
=> x = 34/17
=> x = 2
Put value of x in Equation 2, we get
=> 5x + y = 9
=> 5(2) + y = 9
=> 10 + y = 9
=> y = 9 - 10
=> y = -1
So, x = 2 and y = -1
____________________________________________________________________________________________________
Now, By using Eliminating Method:
=> 2x - 3y = 7 .............(1)
=> 5x + y = 9 .............(2)
Multiply Equation (2) by (-3), we get
=> -15x - 3y = -27 ............(3)
Now, subtract Equation (3) by Equation (2), we get
2x - 3y = 7
-15x -3y = -27
__________
=> x = 2
Put value of x in Equation 2, we get
=> 5x + y = 9
=> 5(2) + y = 9
=> 10 + y = 9
=> y = 9 - 10