Hello, I am having trouble with the explanation for Angles, Triangles, and Polygons problem #2.

Hello, I am having trouble with the explanation for Angles, Triangles, and Polygons problem #2 on page 343. To get the answer to this problem, I multiplied 180*4, as there are four sets of angles that each make up a straight line, and the question asks for their sum. The solution seems to be getting at this, but instead of saying “180° x 4=720°” it says “180°.4 x 180° = 720°”. (I can send you a picture if you want.) Is this a typo, or am I misunderstanding?

Hello, I am a little confused on the solution given on page 332 for problem #6 of “Percents and Percent change.”

Hello, I am a little confused on the solution given on page 332 for problem #6 of “Percents and Percent change”. The first two steps to solving the problem are listed as

1. 7=x/100*56

2. 5/56=x/100

I’m not sure how to get from step 1 to step 2 – or where the 7 in step 1 came from. It seems to me that the 7 in step 1 should be a 5 – as the problem asks for babies born on Thursday, not Tuesday. Is this a typo, or am I missing something?