What is the area of a triangle with vertices at (0,-,-2), and (9,1)

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

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

Binh says the point of intersections is (0,-3) which statements identify the errors binh made , check all that apply