Just like the last problem, they want us to plug in -2 where r is, -3 where s is and 5 where t is. Doing that, we get:
[tex] 2(-2)^2+3(-3)^3-(-2)^2+4(5)^2-(-2)^2 =\\8-81-4+100-4=\\19+8-8=19\\ [/tex]
Your answer is indeed correct!
