Question

1. 5x + 2y = 31
II. 3x + 7y = 36​

Answer 1

Answer:

x=5

y=3

Step-by-step explanation:

5x+2y=31

or,5x=31-2y

or,x=31-2y/5.......(3)

by putting the value of x in equation(2),

3x+7y=36

or,3*31-2y/5=36-7y

or,93-6y/5=36-7y

or,93-6y=5(36-7y)

or,93-6y=180-35y

or,-6y+35y=180-93

or,29y=87

therefore, y=3

By putting the value of y in equation (3) ,

X=(31-2y)/5

or,x=(31-2*3)/5

or, x=31-6/5

or,x=25/5

Therefore,x=5. (ans.)

Answer 2

Answer:

(5x + 2y = 31) × 3

(3x + 7y = 36) × 5

15x + 6y = 93

15x + 35y = 180

29y = 87

y = 87/29

y = 3

15x + 6y = 93

15x + 6×3 = 93

15x + 18y = 93

15x = 93 - 18

15x = 75

x = 75÷15

x = 5

so

y = 3

x = 5