Answer:
1.Therefore the solution of given system is (3,4)
2.Therefore the solution of given system is (-1,2)
Step-by-step explanation:
1.
Given the system
2x +3y =18...........(1)
-2x+5y =14...........(2)
Adding the equation (1) and (2)
2x+3y-2x+5y= 18+14
⇔8y = 32
⇔
⇔y = 4
Putting the value of y in equation (1)
2x + 3. 4=18
⇔2x+12 =18
⇔2x = 18-12
⇔2x = 6
⇔x =3
Therefore the solution of given system is (3,4)
2.
Given the system
3x +4y = 5..........(a)
2x +7y =12...........(b)
Equation (a) ×2 - equation (b)×3
2(3x+4y)- 3(2x+7y) = 2.5 -12.3
⇔6x + 8y -6x -21y = 10-36
⇔ -13y = -26
⇔
⇔y = 2
Putting the value of y in equation (a)
3x +4.2 =5
⇔3x = 5 -8
⇔3x = -3
⇔x = -1
Therefore the solution of given system is (-1,2)