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L1 : y=−4x+3L2 : y=4x−1

1 Answer

4 votes

Answer:

Assuming you're trying to find where the lines intersect (their solution), the point where they intersect is (1/2 , 1).

Explanation:

When you are trying to find the point where two lines intersect, you have to find the x and y values of that point. To do that, just set the lines equal to each other.

First, since y must equal y:

y = y

-4x + 3 = 4x - 1

Now solve for x:

-8x + 3 = -4

-8x = -4

8x = 4

x = 1/2

We just found the x value of the shared point. Now we need to find the y value of that point. Again, since the two lines share this point, plugging in the x value will result in the same y value for both lines.

So just plug in x to any of the equations: (I think y=4x-1 is easier)

y(1/2) = 4(1/2) - 1 or y = 4(1/2) - 1 (it doesn't matter how you write it)

y(1/2) = 2 - 1 or y = 2 - 1

y(1/2) = 1

So the point is:

(1/2 , 1)

To check you can plug in the y value you find, 1 in this case, and solve for x. If you get the same x value as before, everything is correct.

So:

(1) = -4x + 3

-2 = -4x

1/2 = x or x = 1/2

Great! Everything is correct.

This may seem like a very long process, but it is very easy. Just find the x and y values that the lines share by setting the lines equal to each other.

User James Richard
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