What’s an equivalent expression of -1/2(-2x+4y) ?

Enter the number of complex zeros for the polynomial function f(x) = x 4+ 5x² +6

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

The measure of an angle is 117°. what is the measure of a supplementary angle?