find the equation of the line joining the point (2,-9) and the point of intersection of lines 2x+5y-8=0 and 3x-4y-35=0
Answers
In the above Question , the following information is given -
We have to find the equation of the line joining the point (2,-9) and the point of intersection of lines 2x + 5y - 8 = 0 and 3x - 4y - 35 = 0 .
Solution -
Here , we have the following Equations of the lines given as -
Line 1 => 2x + 5y - 8 = 0
Line 2 => 3x - 4y - 35 = 0
Now , to find the required point of Intersection , we have to solve these two equations .
Equation 1 -
=> 2x + 5y = 8
Equation 2 -
=> 3x - 4y = 35
Plotting these on a line graph , we get -
The required Intersection point is ( 9, -2 ) .
See the graph in the attachment for more details .
So , finally , we have got two points through which this line passes -
Point 1 => ( 2, -9 )
Point 2 => ( 9, -2 )
Slope of the above line -
=> [ y² - y¹ ] / [ x² - x¹ ]
=> [ - 2 + 9 ] / [ 9 - 2 ]
=> [ 7 / 7 ]
=> 1
According to the slope intercept form -
y - y¹ = m ( x - x¹ )
As , m , the slope is 1 , this reduces to -
y - y¹ = x - x¹
x¹ = 2
y² = -9
So ,
y - ( - 9 ) = x - 2
=> y + 9 = x - 2
=> x - y - 11 = 0 .
Thus , the required equation is x - y - 11 = 0 .
This is the required answer .
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Note -
Here , I have used the exponential notations to denote the various points .
x¹ stands for x_1 or 2
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☞ You Equation is x-y-11 = 0
We are given,
➝ 2x+5y-8 = 0
➝ 3x-4y-35 = 0
On Solving these Equations
➳ 2(9)+5(-2)-8 = 0
➳ 18-10-8 = 0
➳ 0 = 0
➳ x = 9 and y = -2
Similarly,
➳ 3(9)-4(-2)-35 = 0
➳ 27+8-35 = 0
➳ 0 = 0
➳ x = 9 and y = -2
Therefore the Intersection point is (9, -2)
Now that we found two points through which they pass, that is, (2, -9) and (9, -2)
Slope of them is given by,
➢ (y² - y¹)/(x² - x¹)
➢ {(-2)+9}/{9-2}
➢ 1
As per the slope intercept form,
»» y - y¹ = m( x - x¹ )
The slope is 1 so this reduces to
»» y - y¹ = x - x¹
»» x¹ = 2
»» y² = -9
Finally,
≫ y-(-9) = x-2
≫ y+9 = x-2
≫ x-y-11 = 0 [Ans]
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