Help please this is need sooner or later and whoever answers thins thanks so much!

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?

Select the correct answer from each drop-down menu. let c(g) be the total cost, including shoe rental, for bowling g games at pin town lanes. c(g) = 5g+3 so, c(6) = 8? 33? 30? or 14? this means that for a $6 shoe rental? for $6 per game? for 6 games? for a total cost of $6? , the games are $8 each? total cost is $33? number of games is 14? or total cost is $30? reset next

If f(x)=3 over x+2 - square root x-3 then f(7)=