can you help with how to evaluate?

Question

mv2; m=6 1/2 v=-2/5

Answer 1

mv²

m = 6 1/2, v = -2/5

since m is a mixed number we have to convert it to an improper fraction. To do this, we multiply the denominator by the whole number and add the numerator:

2 * 6 + 1 = 13

The result (13) will be the new numerator and the denominator will remain the same (2). So the improper fraction is:

13/2

(13/2) * (-2/5)² = (13/2) * (4/25) = 26/25 or 1 1/25.

 

 

Answer 2

I generally think that it's easier to work with decimals, especially with these simple, rational fractions.

expression:    mv²
values: m = 6 1/2  v = -2/5
convert values to decimals: m = 6 1/2 = 6.5         v = -2/5 = -0.4
insert values into expression: mv²=(6.5)(-0.4)²
square second term: (6.5)(.16)
final evaluation: mv² = 1.04