Jillian simplified the expression 7+3⋅(10−6)2 in the following way

i don't get it

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

Which of the following is closest to 32.9 x 7.5? a: 232 b: 259 c: 220 d: 265

87.5% , 100% , 83.33 , 93.33% , 100% , 82.5% are all the academic points i've gotten this quarter. what's my final grade?