2(2 1/2)(7 1/2) + 2(7 1/2)(10 1/2) + 2(2 1/2)(10 1/2)=

Question

2ab+2bc+2ac

a=2 1/2, b= 7 1/2, c= 10 1/2.

Answer 1

Given : a = 2 1/2, b = 7 1/2, and c = 10 1/2.

Change the mixed fractions as improper fractions.

a = (2*2 + 1)/2 = (4 + 1)/2 = 5/2,

b = (7*2 + 1)/2 = (14 + 1)/2 = 15/2, and

c = (10*2 + 1)/2 = (20 + 1)/2 = 21/2.

Now 2ab + 2bc + 2ac = 2(ab + bc + ac)

= 2[(5/2*15/2) + (15/2*21/2) + (5/2*21/2)]

= 2[75/4 + 315/4 + 105/4]

= 2 * 495/4

= 495/2.