In the system –12c + 3d = 6 and –3c + 6d = –9, which expression could you use for substitution?

ava gathered data about the age of runners and the time it took them to complete a 5K race and half marathon. Her data is displa

Serggg [28]

Answer: B.

Step-by-step explanation:

I wrote my answer in the comments, but I’ll say it again; the answer is likely B. Because the other options are not very relevant. B. Is the option most likely to be disputed on. I do not know if this is the answer however, but this was what I thought.

7 0

2 years ago

Sal exercised by stretching and jogging 5 days last week.

pashok25 [27]

So sal stretched for about 5 min. each day in 5 days and he jogged for about 43 min ..how??
I divided 215 to 5 and I got 43 min. and how did I get 215 well 240 minus 25 min is 215

and elena she stretches for 75 min in the whole 5 days total and 300 minus 75 is 225. then 225 divided by 15 is 15

Sam jogged for 43 min a day and elena jogged for 15 min a day
I hope this helps :)

4 0

2 years ago

Hazel needs to get to her granddaughter's house by taking an airplane and a rental car. She travels 900 miles by plane and 250 m

Arisa [49]

Answer:

50 pmh

Step-by-step explanation:

Distance traveled by plane = 900 miles

Distance traveled by car = 250 miles

Let the speed of the car is c. The plane travels 250 mph faster than the car, so speed of the plane will be c + 250

Let the time taken to travel on car is t. She traveled 2 hours more on car the she rode on plane. This means she consumed 2 hours less time on plane. So the time spent on plane will be t - 2 hours.

Distance = Speed x Time

For Plane, the equation will be:

900 = (c + 250)(t - 2) <u>Equation 1</u>

Likewise, the equation for car will be:

250 = ct

From here, t = 250/c

Using this value in Equation 1, we get:

$900= (c + 250)(\frac{250}{c} -2)\\\\ 900=250 +\frac{62500}{c}-2c-500\\\\ 1150=\frac{62500}{c}-2c\\\\ 1150c=62500-2c^{2}\\\\ 2c^{2}+1150c-62500=0\\\\ \text{Using the quadratic formula, we get}\\\\ c=\frac{-1150\pm \sqrt{1150^{2}-4(2)(-62500)} }{2(2)}\\\\ c = -625, 50$