Answer:
25$
Step-by-step explanation:
Add all of the days up and divide by 7
B
Here, x is the volume of the 10ml solution. Multiplying it by its concentration gives the amount of alcohol in it. 50 is the total volume of the 12% solution so (50 - x) gives the volume of the 15% solution. Multiplying this by the concentration gives the amount of alcohol in it. The sum of these amounts of alcohols is equivalent to the amount of alcohol in the 12% solution which is given by the product of its volume and concentration.
Y = 40x +15 because it charges 15$ as it's initial service fee and it charges an additional $40 a month so you multiply 40 times the number of months and add 15 to get the total after x amount of months
Answer:
a21 = -61
Step-by-step explanation:


(subtract to eliminate a₁)
9 = -3d
d = -3
-19 = a₁ + (6)(-3)
-1 = a
a21 = -1 + (21 - 1)(-3)
= -61