Help with 1 and 3 please.

How to solve a simultaneous equation involved with fractions?

Need solving this 2nd limit problem.

Sherrie is baking a pie for her family. she leaves the room and comes back to 35% of the pie having been eaten before she can put the topping on. how much 1 square inch strips of dough will she need for the top, now that a portion is missing? round your answer to the nearest while nimber.