To compare their speed (rate), we need to have the same time or same distance to use as a reference.
Matt ran 50 meters per 10 seconds. Molly ran 30 meters per 5 seconds. If she ran for 5 more seconds, she would have gone 30 more meters, for 30 meters per 10 seconds. Thus, Molly went faster.
Alternately, you could calculate their speeds in meters per (one) second and compare. 50 meters per 10 seconds is 5 meters per second, and 30 meters per 5 seconds is 6 meters per second.
ANSWER
When 
is written in the form 
, it looks like 
EXPLANATION
To write in the form , we have to complete the squares.
We add and subtract half the coefficient of 
square.
The first three terms of the function is now a perfect square.
We now simplify rto obtain,
Answer is 2263.
Checkpoint 1 is -86
Checkpoint 4 is 2177
Subtract -86 from 2177....2177-(-86)
=2263
2263 is how much higher checkpoint 1 (-86) is from checkpoint 4 (2177)
Hope this helps! :)
Ok so right now leave the x's alone. Now add/subtract the numbers without variables which would equal to 0 since -1+4 = 3 and 3-3 =0
now 7x+x =8x so 8x is answer
