3x+9y=11,6x+3y=7 xy by elimination method

Question

its about ellimination method

Answer 1

Given equation is  3x+9y = 11

Multiple to each sde by negitve 2.

-6x-18y = -22 ----------> (1)

And 6x+3y = 7 -------------> (2)

To eliminate the x value, add the equations (1) & (2).

-6x-18y = -22

 6x+3y = 7

___________

-15y = -15

Divide to each side by negitive 15.

-15y/-15 = -15/-15

⇒ y = 1

Substitute the value of y in equation (1).

-6x-18*1 = -22

-6x-18 = -22

Add 18 to each side.

-6x-18+18 = -22+18

-6x = -4

Divide to each side by negitive 6.

-6x/-6 = -4/-6

⇒ x = 2/3.

Solution of given equations is x = 2/3, y = 1.