Answer:
15
Step-by-step explanation:
using the rule of exponents
= 
=
=
= 15
Answer: (5,10)
Step-by-step explanation:
multiply first equation with 2 and add it to second to eliminate X
7x-5y=-15 //*2
14x-10y=-30
-14x+7y=0
----------------
-3y=-30
y=-30/-3
y=10
7x=50-15
7x=35
x=35/7
x=5
11-5=6
18-11-7
26-18=8
........... so on and so forth.
I think you get the point.
Answer:
180 coins
Explanation:
N = number of nickels (no nickels spent)
D = number of dimes initially saved
D' = number of dimes left after spending
1) N = D + 43
2) D' = D - 17
3) N = 2*D' = 2*(D - 17)
Set equations 1) and 3) equal to each other and solve for D:
D + 43 = 2*(D - 17)
D + 43 = 2*D - 34
D = 43 + 34 = 77
N = D + 43 = 77 + 43 = 120 nickels left
D' = D - 17 = 77 - 17 = 60 dimes left
Total coins left = 120 + 60 = 180 coins (I hope this is not too confusing for you)