Answer:
180-140=50 180-90-50= 40 m=40
Answer:

Step-by-step explanation:
So when you express a linear function in slope-intercept form it's given in the form of y=mx+b, where m is the slope, and b is the y-intercept. This is because as x increases by 1, the y-value will increase by m (because multiplication), and since the slope is defined as rise/run, the rise will be m, and run will be 1, giving you a slope of m/1 or m. The reason b is the y-intercept, is because whenever the linear function crosses the y-axis, the x-value will always be 0. Meaning that mx will be 0 because m * 0 will equal 0... and that leaves b by it self, so b will determine the y-intercept.
So if you look at the graph, the linear function crosses the y-axis as (0, 2) so the value of b will be 2. This gives you the equation y=mx+2.
Now to calculate the slope, we can take any two points and see how much the rise was and how much the run was. It can also be more formally defined in the equation:
. So let's take the points (0, 2) and (8, 8). As you can see the x-value increases by 8 or "ran" by 8, and the y-value increased by 6. So the rise over run in this case is 6/8 which can simplified as 3/4. That is the slope. This gives you the complete equation of: 
Answer:
C
Step-by-step explanation:
68 - 80 / 80
= - 12 / 80
= - 3 / 20
= - 15%
It is 12 since 1/6=6^-1=6
implies 2*6=12
The goal here is to find the cost of the painting BEFORE the 60% increase.
To find the cost of the painting, we must take in the information we already have:
Increase percent: 60%
Original price: unknown
Price after increase: $400
$400 is the price of the painting AFTER the increase has been added. So this equals the cost of the painting before the increase, plus the total amount of the increase (which is 60% of the original price).
The total must be (100% + 60% = 160%) 160% of the original painting price.
To find the original price, we must divide the increased price by the new percentage (160%). But how do we get here?
Well, we have 160% and our (fraction) $400/1%. We will have to switch the 160% and the 1%, giving us..
1% $400/160%
We take 400/160, which is 2.5. But this is only 1% of the original price! We want 100%.
So now, we multiply the 2.5 by 100 to get our answer: $250.
I hope this helps! If you have any questions, feel free to ask.