Найдите сумму a+b, если для двузначного числа ab имеет место равенство ab=2a+4b

Lisa has three classes that each last 50 minutes. what is the total number of minutes of the three classes

Parabolas y=−2x^2 and y=2x^2 +k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.

Atorch and a battery cost 2.50 altogether.the torch costs 1.50 more than the battery.what fraction of the total price is the torch? give your answer in its simplest form.