Simplify (a + b - c)(a + b + c)

a^2 + b^2 - c^2 + 2ab

Step-by-step explanation:

(a + b - c)(a + b + c)

1. expand

(a^2 + ab + ac + ba + b^2 + bc - ca - cb - c^2)

2. rearrange,

(a^2 + b^2 - c^2 + ab + ba + ac - ca + bc - bc)

3. add and subtract

(a^2 + b^2 - c^2 + 2ab)

a = 11 : 4

b = 38

c = 1 for every 6

probability for j is 1/4

while

a is 1/6