<span>Two cars run at constant speeds around a one-mile racetrack. If the cars circle the track in the same direction, the faster car passes the slower car every 10 minutes. If the cars circle the track in opposite directions, the cars meet every 30 seconds.</span>
We have this equation for the slope is: y=mx+b which m is the slope and b is the y-intercept, so we have y=20-15x or y=-15x+20, and we already know that the slope is -15 and y-intercept is 20. As a result, the student's error is that he thinks that 20 is the slope because it is the first number. Hope it help!
Actually, she worked for seven hours, so I'll solve for that.
7.20 x 3 = 21.6
6.75 x 4 = 27
21.6 + 27 = 48.6
48.6 /2 = 24.3
Her average should be $24.3 If she did work six hours, just multiply 6.75 x 3 and do what I did.
Answer: 2 hr.
Explanation: Think back to rate of change. <em>d</em> = <em>rt</em>, <em>r</em> = <em>d/t</em>, <em>t</em> = <em>d/r</em>. In this case, we will be using <em>d</em> = <em>rt</em>. Mph would be <em>r</em>, rate, so you would categorize 15 mph and 8 mph under rate. <em>t</em> should represent the time each cyclist traveled. Tracey's and Emma's distance, <em>d</em>, would be the same as their mph, hence Tracey's being 15<em>t</em> and Emma's would be 8<em>t</em>. When you add Tracey's distance plus Emma's distance, you end up with 46 mi. Now, you need to combine like terms, which should look like 15<em>t</em> + 8<em>t </em> = 46. Add 15 and 8 to get 23, so it should be 23<em>t</em> = 46 now. Then, divide both sides of the equation by 23 and now you should have your answer, <em>t</em> = 2 hr.
Amalia. Phones rule is only true with numbers between 1 and 1,000.
