Using the discriminant determine the number of real solutions -4x^2+20x-25=0
a: no real solution
b: one real solution
c: two real solutions

17 in long 1.3 ft wide and 8in high what is the volume

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

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?