Advertisement Remove all ads

Solve Each of the Following Systems of Equations by the Method of Cross-multiplication 3x + 2y + 25 = 0 2x + Y + 10 = 0 - Mathematics

Solve each of the following systems of equations by the method of cross-multiplication 

3x + 2y + 25 = 0
2x + y + 10 = 0

Advertisement Remove all ads

Solution

The given system of equation is

3x + 2y + 25 = 0
2x + y + 10 = 0

Here

`a_1 = 3, b_1 = 2, c_1 = 25`

`a_2 = 2, b_2 = 1, c_2 = 10`

By cross-multiplication, we have

`=> x/(2xx 10-25xx 1) = (-y)/(3xx 10- 25xx 2) = 1/(3xx1 - 2xx2)`

`=> x/(20-25) = (-y)/(30-50) =- 1/(3-4)`

`=> x/(-5) = (-y)/(-20) = 1/(-1)`

Now `x/(-5) = 1/(-1)`

`=> x = (-5)/(-1) = 5`

And 

`(-y)/(-20) = 1/(-1)`

`=> y/20 = 1`

=> y = -20

Hence, x =  5, y = 20 is the solution of the given system of equations.

  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

RD Sharma Class 10 Maths
Chapter 3 Pair of Linear Equations in Two Variables
Exercise 3.4 | Q 2 | Page 57
Advertisement Remove all ads
Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×