The table shows the number of miles people in the U. S. traveled by car annually from 1975 to 2015. The equation for the line of best fit is y=0.048x​+1.345, where x is the number of years since 1975 and y is the number of​ vehicle-miles traveled in trillions. What do the slope and​ y-intercept represent? Estimate the number of miles people in the U. S. traveled in 2007. What is a reasonable prediction for the number of miles people in the U. S. will travel in​ 2022? Year ​Vehicle-Miles Traveled in U. S.​ (in trillions): 1975 1.298 1980 1.529 1985 1.720 1990 2.118 1995 2.387 2000 2.697 2005 2.973 2010 2.945 2015 3.055 What does the slope​ represent? Select the correct choice below and fill in the answer​ box(es) to complete your choice. ​(Type an integer or a​ decimal.)

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the   (original price) is $420.

0.7x   = 420

equation image indicator

x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

equation image indicator

x = 600

the original cost was $600.  

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

equation image indicator

x = 21,600

hermione earned $21,600 per year before the pay raise.

this is an example so maybe you will get how to at least do it!

yes yes yes yes yes yes yes yes yes

40 minutes

step-by-step explanation:

add the time and multiply by 2