Point of Intersection Question10

In this page Point of Intersection Question10 we are going to see solution of second question in the worksheet point of intersection.

What does mean by point of intersection:

If two straight lines are not parallel then they will meet at a point.This common point for both straight lines is called the point of intersection.If the equations of two intersecting straight lines are given,then their intersecting point is obtained by solving equations simultaneously.

Find the intersection point of the straight lines 2 x - y = 15  and

5 x + 3 y = 21

Solution:

2 x - y = 15   ----- (1)

5 x + 3 y = 21 ------(2)

In the first equation coefficient of x is 2,in the second equation the coefficient of x is 5 and we have same signs for both equations. But the coefficient of y in the first equation is -1 and coefficient of y in the second equation is 3 and we have different signs.

To make the coefficient of y of the first equation as 3 we need to multiply the the whole equation by 3.

Then we are going to add the first and second equation since we have different signs.

(1) x 3 = >            6 x - 3 y = 45

5 x + 3 y = 21

6 x - 3 y = 45

5 x + 3 y = 21

--------------------

11 x   = 66

--------------------

x  = 66/11

x = 6

Substituting x = 6 in the first equation

2 (6) - y = 15

12 -  y = 15

- y = 15 - 12

- y = 3

y = -3

So the intersection point of the straight lines is (6,-3).

Point of Intersection Question10 to Analytical Geometry 