Xiao teacher asked him to rewrite the sum 60+90 as the product of the gcf of the two numbers and a sum xiao wrote 3(20+30) what mistake did xiao make how should he have written the sum

Write 17/20 as a decimal and as a percent.

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

This is different from the first one can someone me