Ab and bc are tangent to circle d. find angle b if arc aec measures 210 degrees

Which problem could be  solved  by evaluating the expression  7×(−3)7×-3?

Louise measured the perimeter of her rectangular scrapbook to be 154 cm. if the scrapbook is 45 cm wide, how long is the scrapbook?

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?