r△s is defined as 2r^2 + s^2 + 4rs. What is the value of -2△-1?

Question

1.) -17

2.) -1

3.) 1

4.) 17

Answer 1

Based on the given notation, we can assume that r = -2 and s = -1. That means that we have

2r^2 + s^2 + 4rs = 2(-2)^2 + (-1)^2 + 4(-2)(-1)

= 2 * 4 + 1 + 8

= 17