What is the correct formula for calculating a 3 x 3 determinant?

To work out the determinant of a 3×3 matrix:

Multiply a by the determinant of the 2×2 matrix that is not in a's row or column

Likewise for b, and for c

sum them up, but remember the minus in front of the b

Hope this helps, stay safe, have a good day :D

i dony know

step-by-step explanation:

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.