Sherry uses the steps below to solve the equation x+ (-8) = 3x+6

step 1

step 2

step 3

step 4

add 1 negative x-tile to both sides and create zero pairs

add 8 positive unit tiles to both sides and create zero pairs.

divide the 14 unit tiles evenly among the 2 x-tiles

the solution is x= 7

what is sherry's error?

There are two major tests of readiness for college: the act and the sat. act scores are reported on a scale from 1 to 36. the distribution of act scores in recent years has been roughly normal with mean µ = 20.9 and standard deviation s = 4.8. sat scores are reported on a scale from 400 to 1600. sat scores have been roughly normal with mean µ = 1026 and standard deviation s = 209. reports on a student's act or sat usually give the percentile as well as the actual score. the percentile is just the cumulative proportion stated as a percent: the percent of all scores that were lower than this one. tanya scores 1260 on the sat. what is her percentile (± 1)?