What is the x and y intercept of x-y=5xy=5?

1 Answer
Nov 30, 2014

Intercepts are the points where the graph crosses the coordinate axes.

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Notice how at the Y Intercept the value of the x-coordinate is 0, and at the X Intercept, the value of the y-coordinate is 0. We can use this principle to find the x and y intercepts!

1. To find x intercept

Substitute y=0y=0 in the given equation, and solve for xx.

x-0=5x0=5
x=5x=5

Therefore, x intercept =(5,0)=(5,0)

2. To find y intercept

Substitute x=0x=0 in the given equation, and solve for yy.

0-y=50y=5
y=-5y=5

Therefore, y intercept =(0,-5)=(0,5)


Another way to do this in to remember the intercept form of an equation of a line, i.e.,

x/a+y/b=1xa+yb=1

where
aa is the x-intercept
bb is the y-intercept

Given equation: x-y=5xy=5
To make the RHS = 1, we'll divide throughout by 5, getting:

x/5-y/5=1x5y5=1

=> x/5+y/-5=1x5+y5=1

Notice how this looks like the intercept form of an equation of a line.

Comparing the two equations, we can conclude
a=5a=5 and x intercept=(5,0)=(5,0)
b=-5b=5 and y intercept=(0,-5)=(0,5)