Question

8x-5y=21 simultaneous linear equation
2x+9y=-5

Answer 1

`x=2` and
`y=-1`

Explanation:

If two equations are given, we can solve one of the equation in terms of single variable and put it in the other equation which will further give the value of x and y.

For the given equations:

`8x-5y=21` Equation:1

`2x+9y=-5` Equation:2

Solving equation multiply equation 2 with 4 on both the sides

`8x+36y=-20` Equation 3

Subtracting Equation:3 from Equation:1

`8x-5y-(8x+36y)=21-(-20)\\8x-5y-8x-36y=21+20\\-41y=41\\y=-1`

Putting value of 'y' in Equation:2 which will give the value of x

`2x+9y=-5\\2x+9(-1)=-5\\2x-9=-5\\2x=4\\x=2`