Tell whether the fraction is in simplest form 25/42

Determine whether the graphs of y=8x+5 and -y=8x-5 are parallel, perpendicular, coincident, or none of these. a. coincident b. parallel c. perpendicular d. none of these

Could someone with number 1 and 2

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?