Question #e7d7d

1 Answer
Mar 18, 2017

Answer:

See explanation

Explanation:

Compare to the standardised equation of a strait line #y=mx+c#

Where #m# is the gradient (slope) and #c# is the y-intercept.

Given:

#y=x+1#
#y=x-1#

Although not written the variable #m# is there. It is of value 1.

So both lines have the same gradient (slope -> m=1)

As each 'crosses' the y-axis (y-intercept) in different places and they are parallel to each other they never cross, So there is not a common value

THUS IT IS #ul("WRONG")# TO STATE THAT: #" "x+1=y=x-1#
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I am only doing this for one of the equation. You can do the other one by following the same method.

For #y=x+1#

Determine the x-intercept (crosses the x-axis at #y=0#)

Set #y=0=x+1#

Subtract 1 from both sides #=> x=-1#

Determine the y-intercept (crosses the y-axis at #x=0#)

Set #x=0 ->y=0+1 => y=1#
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Tony B