1.That there is still slavery in the word. CNN 10 reporters caught on film a slave trade in Africa
2. Extra information is adding more information in your sentence to make it seem more interesting
The regression line equation is

, the value of the slope is shown as constant 16 and it's a positive constant, hence the correlation between the amount of gas used and degree of the days is a POSITIVE correlation.
Number of nickels plus number of dimes equals total number of coins
so
n + d = 40
then they tell us that "there are seven times as many dimes as there are nickels"
this translates to
d = 7n
we then plug that into our first equation
and get
n + 7n = 40
then we solve for n
add like terms
8n = 40
then divide both sides by 8
n = 40/8 = 5
therefore Jimmy has 5 nickels