Write an appropriate direct variation equation if y = 45 when x = 5.
1 answer:
You might be interested in
Answer:
Step-by-step explanation:
See the figure below.
This is how you graph directly from the equation in the slope-intercept form (y = mx + b) without having to create a table of x and y values.
The equation is
y = -2/3 x + 1
Compare it with
y = mx + b
b = 1
The y-intercept is 1, so mark 1 on the y-axis. (You already did.)
I placed a black dot there.
The slope is m.
m = -2/3
slope = m = rise/run
A slope of -2/3 can be though of as -2 rise and 3 run. That means start from the y-intercept, and go -2 in y (a rise of 2 down) and 3 in x (a run 3 right). Point graphed in red.
Mathematically, -2/3 is the same as 2/(-3), so starting again from the y-intercept, this slope can also be though of as rise of 2 in y (a rise of 2 up) and a run of -3 in x (a run of 3 left). Point graphed in green.
The line is graphed in blue.
