Question 645379: Hi there i need your help
can you please help me answer this question. im realy not sure where even to start.
here is the question:
A girl saves $1 and $2 coins. She takes it to a bank, she has 180 coins in total that equals $260. Use simultaneous equations to work out how many $1 and $2 coins there are.
thank you
nichola
Answer by nerdybill(7384)   (Show Source):
You can put this solution on YOUR website! A girl saves $1 and $2 coins. She takes it to a bank, she has 180 coins in total that equals $260. Use simultaneous equations to work out how many $1 and $2 coins there are.
.
Let x = number of $1 coins
y = number of $2 coins
.
from:"she has 180 coins" we get equation 1:
x+y = 180
.
from:"total that equals $260" we get equation 2:
x + 2y = 260
.
solve equation 1 for y:
x+y = 180
y = 180-x
substitute above into equation 2:
x+y = 180
x + 2(180-x) = 260
x + 360-2x = 260
360-x = 260
-x = -100
x = 100 (number of $1 coins)
.
Number of $2 coins:
x+y = 180
100+y = 180
y = 80
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