#### notes

3) Cross Multiplication Method- To understand this method properly we shall take help of a example

`4x+2y-7=0` ......eq1

`5x+3y-8=0` ......eq2

While practicing this method if we want to find value of a particular variable we will take that variable as a numerator and the denominator will be the substraction between the cross multiplication of coefficients of the remaining two variables. Like in this case it will be like

`x/"(2×-8)-(-7×3)"`

`y/"(4×-8)-(-7×5)"`

`1/"(4×3)-(2×5)"`

All of them are equal to each other, so if you to find value of x then take,

`x/"(2×-8)-(-7×3)" = 1/"(4×3)-(2×5)"`

`x/"-16+21"=1/"12-10"`

`x/5= 1/2`

`x=5/2`

To find the value of y,

`y/"(4×-8)-(-7×5)"= 1/"(4×3)-(2×5)"`

`y/"-32+35" = 1/"12-10"`

`y/3 = 1/2`

`y= 3/2`

#### Video Tutorials

#### Shaalaa.com | Pair of Linear Equation in two variable part 14 (Algebraic Cross Multiplication)

##### Series 1: playing of 3

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