20 less than 12 times a number is 64. what is the number

How can you construct perpendicular lines and prove theorems about perpendicular lines

How do you write y-10=2 (x-8) in standard form

Parabolas y=−2x^2 and y=2x^2+k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.