Question

Solve the equation by substitution method 2x-7y =3 4x+y=21

Answer 1

Answer:  value of x=5

               value of y=1

Step-by-step explanation:

Given equation,

                              2x-7y=3         -                (equation 1)

                              4x+y=21        -                 (equation 2)

From equation 1,

2x=3+7y

x=(3+7y)/2

Now substituting value of x in second equation,

4x+y=21                    (equation 2)

4(3+7y)/2+y=21

2(3+7y)+y=21

6+14y+y=21

15y=21-6

15y=15

y=1

Therefore y value is 1

Substitute y value in equation 1,

x=(3+7y)/2

x=(3+7)/2

x=10/2

x=5

Therefore x value is 5