12+6x was subtracted from the left but only 12 was subtracted from the right.
6x and 6 are not equal unless x=1
X=-11/15
Answer:
Step-by-step explanation:
x + 3y = 24.....multiply by -1
5x + 3y = 36
------------------
-x - 3y = -24 (result of multiplying by -1)
5x + 3y = 36
------------------add
4x = 12
x = 12/4
x = 3 <=======
x + 3y = 24
3 + 3y = 24
3y = 24 - 3
3y = 21
y = 21/3
y = 7 <========
Answer:
Ok thats really cool thanks :)
The value of the coin times the number of coins all added up equals the total value of the piggy bank
so
0.05n + 0.10d = 5.60
then they have given us "number of nickels is 8 less than 3 times the dimes"
this translates to
n = 3d - 8
we plug this into our first equation and we get
0.05(3d - 8) + 0.10d = 5.60
now we solve for d
first we can distribute the 0.05
0.15d - 0.40 + 0.10d = 5.60
then we can add the 0.15d and 0.10d together
and get
0.25d - 0.40 = 5.60
then we can add 0.40 to both sides
0.25d = 6.00
then divide both sides by 0.25
d = 6.00 / 0.25 = 24
so we have 24 dimes
then to find nickels, we plug in 24 for d into
n = 3d - 8
and get
n = 3(24) - 8
n = 72 - 8
n = 64
therefore we have
64 nickels
and
24 dimes
