Which mathematical concepts were the result of rene descartes

Alley has 10 kittens, and 4 puppies for sale. 4 of the kittens are girls and 6 are boys. 3 of the puppies are boys, and 1 is a girl.

The perimeter of a rectangle is 50 feet and its area is 154 feet. What are the dimensions of the rectangle

Susie is participating in a bake sale for a fundraiser. She baked 8 pies to sell. Two pies weigh 105 g each, one pie weighs 106 g, two pies weigh 108 g each and the last three pies weigh 103.5 g, 102 g and 104.5 g.

Jenna has a savings account invested in stocks and bonds. 20% of her savings is in bonds. If Jenna has $2,200 in bonds, how much does she have in savings all together? I got the right answer guys it is 11,000

19 - [1/4+1/5]=the answer

What is the slope of 4/3 and 6,2

5=-10x-10y What's the slope for this parellel line?

8t-r=12t, solve for t

Joseph sees 4 2/3 doughnuts sitting on a table. Unable to restrain himself, he gobbles down 3/4 of the 4 2/3 doughnuts. How many doughnuts does he eat?

You earned $204 from your job last week. You have two relatives with birthdays coming up and you want to spend the same amount on each of them. You want to still have $80 left over. How much do you spend on each gift?