What is the value of x? 3 (x - 2) + 5x = 18

Janet drove 300 miles in 4.5 hours. write an equation to find the rate at which she was traveling

Solve the equation by completing the square. x^2+2x=17

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?