Respuesta :

Hi there

5a + d - bc
for a = 5, b=7, c=2 ,d =4
5(5) + 4 -7(2)
25+ 4 - 14
21 - 14
7

I hope that's help ! 

5 x 5 + 4 - 7 x 2 = 25 + 4 - 14 =15

or
15