Question 881402
When you plot a graph, whatever you plot
on the vertical axis DEPENDS on what you
plot on the horizontal axis.
The INDEPENDENT variable is plotted on
the horizontal axis.
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In this case, area in square feet is
on the horizontal axis, and
the monthly rent is on the vertical axis
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Let {{{ x }}} = area of an apartment in square feet
Let {{{ R }}} = the monthly rent of an apartment
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You are given the poihnts
( 820, 1510 ) and
( 970, 1660 )
Use the point-slope formula:
{{{ ( R - 1510 ) / ( x - 820 ) = ( 1660 - 1510 ) / ( 970 - 820 ) }}}
{{{ ( R - 1510 ) / ( x - 820 ) = 150 / 150 }}}
{{{ ( R - 1510 ) / ( x - 820 ) = 1 }}}
{{{ R - 1510 = x - 820 }}}
(A)
{{{ R = x + 690 }}}
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check:
( 820, 1510 )
{{{ 1510 = 820 + 690 }}}
{{{ 1510 = 1510 }}}
OK
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(B)
{{{ x = 900 }}}
{{{ R = x + 690 }}}
{{{ R = 900 + 690 }}}
{{{ R = 1590 }}}
The rent is $1,590
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(C)
{{{ R = x + 690 }}}
{{{ 1300 = x + 690 }}}
{{{ x = 610 }}}
The area is 610 square feet