Answer:
D
Step-by-step explanation:
using the definition of n
= 
where n! = n(n- 1)(n - 2)......× 3 × 2 × 1
here n = 7 and r = 4, hence
7
= 
= 
← cancel 3 × 2 × 1 leaving
7 = 7 × 6 × 5 × 4 = 840 → D
Answer:
-8
Step-by-step explanation:
If we let x and y represent the first and second numbers, respectively, we can write the problem statement as the equations ...
We can multiply the first equation by -9 and add 4 times the second equation to get an equation in y alone:
-9(4x +5y) +4(9x +2y) = -9(-28) +4(11)
-37y = 296 . . . . . simplify
296/-37 = y = -8 . . . . . divide by the coefficient of y
The second number is -8.
Here, our equation is 3/5 (0.6) mile per 1/4 (0.25) hour. 0.25 times 4 = 1, so we have to multiply 1/4 (0.25) 4 times to get 1 mile. To get a proportional answer, we must also multiply 3/5 (0.6) by 4. This comes out to 2.4. So her walking rate is 2.4 miles per hour.
Answer:
19 for each one
Step-by-step explanation:
Divide 57 by 3
