15x-10y = 10

did I do it right?​

If i have 20$ and i gave 5$ away how much i got

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 value is a discontinuity of x squared plus 8 x plus 4, all over x squared minus x minus 6?