How did Rene descartes discover the coordinate plene?

What is 7 gal to 10 qt in simplest form? 80 is what percent of 20? How much is 80 percent of 500? How long does it take to travel 1022 miles? What is the difference in -129 degrees Celsius and -81 degrees Celsius? How do you write seven thousandths as a decimal is standard form? What percentage of 23 is 50? How do you write 'seventy thousand two hundred and six' in figures? What times what equals -168? Is 29 a natural number? Does 42 divided by 1428 equals 34? How many open syllables do arena have? What is the monolgoue for Caesars scene 1 line 58-73? What is some thing that looks like a square pyramids? What do you need on 12 ft inflatable dinghy? What times 3 equals 70? What is the name of an eighteen sided shape? What is jacobi identity for three vector ab and c? What is .03 as a percentage? What is the largest number in the roman numerals?