Question

3x + 5y - 12 = 0, x - 3y + 10 = 0 in solve substitution​

Answer 1

Answer:

3x + 5y = 20 equation 1

x + 3y = - 10 equation 2

multiple by equation 1 by 3

and equation 2 by 5

let's add equation 1 and 2

15x + 15y = 20

5x + 15y = -50

-. -. - substract

10x = 70

x =7

place x =7 in equation 1

3x (7) + 5y =20

21 + 5y = 20

5y = 20 - 21

5y = 1

y = 1

5

solution of x y is 7 , 1

5

Answer 2

3x + 5y = 12---------eqn1

And x - 3y = 10-----eqn2

From eqn2, we have

x - 3y =10

= x = 10 - 3y

Substituting x = 10 - 3y

3(10 - 3y)+ 5y = 12

30 - 9y + 5y = 12

30 - 14y = 12

14y = 12+30

14y = 42

y = 42/14 = 3

y = 3

Substituting y = 3 in eqn2

x = 10 - 3(3)

= x = 10 - 9

= x = -1

x = -1 and

y = 3