Question

If C=4 & D=3
2c^2-5d=?

Answer 1

C^2= 16, 2 x 16 = 32.
5d = 5 x 3= 15
32 - 15 = 17

Answer 2

Just plug in the values. Use PEMDAS

2(4)^2 - 5(3)
2(16) - 5(3)
32 - 15
17 <----------Answer