lav123lavsrk
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the line L1 has equation 2x + y = 8. The line L2 passes through the point A ( 7, 4 ) and is perpendicular to L1 . Find the equation of L2.

Answer :

vannialvionitaovavh6
the formula to find linear eqution of graph is
y=mx+c
m= gradient
c= y intercept

first find what is the gradient of L1. In order to get the gradient make y the subject. thus,
2x+y=8
y=-2x+8
thus, the gradient of L1 is -2.

The question states that L2 is perpendicular to L1, thus the gradient of L2 is reciprocal to gradient of L1.
Thus, gradient of L2 will be
m= 1/2

In order for the gradient to be reciprocal, it needs to be perpendicular.
thus so far the equation of L2 is
y= 1/2x+c
Now the question states that is passes through A(7,4). Thus you need to sub in x=7 and y=4 into equation of L2 to find what is the y intercept.
4= 1/2(4)+c
c=2
thus the equation of L2 is
y=1/2x+2
JeanaShupp

Answer:   [tex]x-2y+7=0[/tex]

Step-by-step explanation:

Given : The  line[tex]L_1[/tex] has equation [tex]2x + y = 8[/tex]

In intercept form : [tex]y =-2x+8[/tex]

The slope of [tex]L_1[/tex] =-2    [in intercept form equation of line [tex]y =mx+c[/tex], m is slope ]

Let p be slope of  [tex]L_2[/tex]

We know that when two lines are perpendicular then the product of their slopes is -1.

[tex]\Rightarrow\ -2\times p=-1\\\\\Rightarrow\ p=\dfrac{1}{2}[/tex]

The equation of line having slope 'm' and passing through (a,b) is given by :-

[tex](y-b)=m(x-a)[/tex]

Then , equation of line  [tex]L_2[/tex] will be :-

[tex](y-7)=\dfrac{1}{2}(x-7)\\\\\Rightarrow\ 2y-14=x-7\\\\\Rightarrow\ x-2y+7[/tex]

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