To figure out the average of Michael and Melissa we must add up all their test scores and divide the by 7; which is the number of tests they took.
Michael:
(80+76+73+70+40+25+10)/7
Melissa:
(88+83+75+70+60+65+62)/7
Michael's average is 53.4
Melissa's average is 71.9
So Melissa is earning a C in Latin.
7x + 2y = 48
7x + (2x3) =48
7x + 6 = 48
7x = 48 - 6
7x = 42
--> x = 6
X-27=-1
x represents unknown number
5.100 x 10⁻³ = 5.100 x 0.001
= 0.005100 (shift the decimal point for 5 by 3 units left)
Alternatively, because 10⁻³ = 1/1000, therefore
5.100 x 10⁻³ = 5.1/1000
0.0051
---------------
1000 | 5.100
5000
-------------
1000
1000
This yields the same result.
Answer: b. 0.005100
Normally feet, I don't really understand your question