Question 234168: I REALLY need help with this please! It's a big question but please help as much as you can.
Consider the function y - 5 = -4x
a) Write the equation in standard form.
b) Write the equation in slope-intercept form.
c) The slope is______________.
d) The y-intercept is______________.
e) Graph the function using the slope-intercept method of graphing.
Please help, and please explain your answer so I can hopefully understand it as well. Thank you!
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Consider the function y - 5 = -4x
:
a) Write the equation in standard form.
The standard form is ax + by = c
y - 5 = -4x
add 4x to both sides to get 4x on the left
4x + y - 5 = 0
add 5 to both sides to get the numeral (c) on the right, results
4x + y = 5; this is the standard form
:
b) Write the equation in slope-intercept form.
The slope intercept form is y = mx + b
y - 5 = -4x
Add 5 to both sides
y = -4x + 5; this is the slope/intercept form
:
c) The slope is: in the above equation note that the slope (m) is -4
:
d) The y-intercept is 5 (b).
:
e) Graph the function using the slope-intercept method of graphing.
:
Using the slope/intercept equation y = -4x + 5
Substitute a value for x and find y
x = -1
y = -4(-1) + 5
y = +4 + 5
y = 9
Plot this x/y point: -1,9
:
x = +1
y = -4(1) + 5
y = -4 + 5
y = 1
Plot this x/y point: 1,1
;
this is linear graph (straight line) we only need to plot the two points
the graph should look like this:
Note that this agrees with the two points, -1,9 and 1,1
Also see the y intercept occurs when x = 0, then y = 5
;
:
Did this shed some light on this stuff for you??
Question? ankor@att.net
:
Response to comment:
That does present a problem but can be overcome by plotting a point that falls
within this graph
you can see we are limited but lets plot the point for:
x = +2
y = -4(2) + 5
y = -8 + 5
y = -3
Plot this x/y point: +2, -3
:
So we have 2,-3 and 1, 1 as the points we can plot here
Also I should mention the y intercept is an easy one to plot, (when x=0), the
point where the line crosses y axis, in this case 5, can be used
:
You can choose what values of x you wish to plot, if one doesn't work try
another, with a little practice you will see what is best.
:
Did this help answer your question on this? Let me know please.
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