seven years ago beths son was one third her age at the time. seven years from now he will be one half her age. how old is beth's son

Can someone check my answer? you : )

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

What is the value of d? 9d = –5.4 d =