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
Answer:

Step-by-step explanation:

Distribute negative sign.

Combine like terms.


C. (3x+1)(3x-2) 3x times 3x= 9x^2 and 3x times -1= -3x
2 times 3x= 6x and 2 times -1= -2
9x^2- 3x+6x-2
9x^2+3x-2
Hope I explain this more clearly for you.
Based on the numbers we have we can assume that she saves 3 times more each week than the last (1*3=3, 3*3=9).
Following this trend we would multiply the amount she saved the third week ($9) by 3 to get $27 for the fourth week.
Then, we would multiply the amount she saved the fourth week ($27) by 3 to get $81 for the fifth week.
Finally, to figure out how much she saved in the 5 weeks, we need to add each value up to get 1+3+9+27+81= $121 saved in 5 weeks
Answer is 18
I found it by multiplying 20 by .90