The original price is $450.
<u>Step-by-step explanation:</u>
Step 1:
Given details, Discount%, D% = 30 and Selling Price, SP = $315
Step 2:
Write down formula for calculating the Original Price
Selling Price (SP) = Original Price (OP) - Discount (D)
Discount (D) = Original Price (OP) * (D%/100)
Step 3:
Substitute given values in the formula
315 = OP - D
D = 
D = 0.3 OP
Step 4:
Substitute value of D in the first formula
315 = OP - 0.3 OP
315 = OP (1 - 0.3) = 0.7 OP
Original Price, OP = 315/0.7 = $450
Slope-intercept form:
y = mx + b
"m" is the slope, "b" is the y-intercept (the y value when x = 0)
You need to find "m" and "b".
If you look at the graph, when x = 0, y is 1, so the y-intercept is 1.
y = mx + 1
To find "m", you can use the slope formula and find two points on the graph and plug it in, or you can use this:

Rise is the number of units you go up(+) or down(-)
Run is the number of units you go to the right.
If you look at the graph, from each point you go up 1 unit, and to the right 1 unit. So your slope is
or 1
y = 1x + 1
y = x + 1
I need help to find the root?
Subtract 13.09 from 21.59 giving you 8.5. Since the amount of space on both the left and right margin have to be equal you would divide by 2 to get 4.25 on the left margin as well as the right.