Question

4p² - pq² para p = 4 e q = 1

Answer 1

4p² - pq²
4*4² - 4*1²
4*16 - 4*1
64 - 4
60

Answer 2

4p² - pq²

para 

p = 4
q = 1

===
4p² - pq²
4.(4)² - 4 . (1)²
4 . 16 - 4 . 1
64 - 4
=> 60