Space is a way of joining together points, lines, and

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.