x=2y
z+5=2y
0.25x+0.05y+0.10z=12.10
Explanation
Step 1
Let
She has a total of $12.10 in quarters, nickels and dimes.=
[tex]\text{total = 1}2.10[/tex]a quarter =0.25 usd
a nickels=0.05 usd
a dime=0.10 usd
x= amount of quartes
y=amount of nickels
z=amount of dimes
total=0.25x+0.05y+0.10 z
Step 2
She has double the amount of quarters compared to nickels, in other words you have to multiply the amount of nickes by 2 to obtain the amount of quarters
[tex]x=2y[/tex]Also, The number of dimes is 5 less than twice the number of nickels, in other words, you have to add 5 to the number of dimes to obtain twice the number of nickels
[tex]z\text{ +5=2y}[/tex]Step 3
total
[tex]0.25x+0.05y+0.10z=12.10[/tex]and that's all, now you have a system of 3 equations and 3 variables(x,y,z)
