Alvin's age is two times Elga's age. The sum of their ages is 81 . What is Elga's age?

Leo has b boxes of pencils. each box contains 6 pencils. he has a total of 42 pencils. the equation that represents this situation the value of b that makes the equation true the first one is b+6=42,6b=42,b=42+6,or 42b=6 the second one are 7,836 48

Equation for the calculation double 2 and then add 5

Which of these tools or constructions is used to inscribe a hexagon inside a circle?