Sagot :
Make a system of equations.
[tex]\sf0.10d+0.25q=6[/tex]
[tex]\sf~q = 2d[/tex]
Plug in 2d for 'q' in the first equation:
[tex]\sf0.10d+0.25q=6[/tex]
[tex]\sf0.10d+0.25(2d)=6[/tex]
Multiply:
[tex]\sf0.10d+0.50d=6[/tex]
Combine like terms:
[tex]\sf0.60d=6[/tex]
Divide 0.60 to both sides:
[tex]\sf~d=10[/tex]
Now plug this into any of the two equations to find 'q':
[tex]\sf~q = 2d[/tex]
[tex]\sf~q = 2(10)[/tex]
[tex]\sf~q = 20[/tex]
So she has 10 dimes and 20 quarters.
[tex]\sf0.10d+0.25q=6[/tex]
[tex]\sf~q = 2d[/tex]
Plug in 2d for 'q' in the first equation:
[tex]\sf0.10d+0.25q=6[/tex]
[tex]\sf0.10d+0.25(2d)=6[/tex]
Multiply:
[tex]\sf0.10d+0.50d=6[/tex]
Combine like terms:
[tex]\sf0.60d=6[/tex]
Divide 0.60 to both sides:
[tex]\sf~d=10[/tex]
Now plug this into any of the two equations to find 'q':
[tex]\sf~q = 2d[/tex]
[tex]\sf~q = 2(10)[/tex]
[tex]\sf~q = 20[/tex]
So she has 10 dimes and 20 quarters.
.10x = dimes ----------\
+ 6.00
2(.25x) = quarters---/
.10x + 2(.25x) =6.00 .10(10) + 2(.25(10)) =6.00
10x + 50x = 600 1 + 2(2.50) = 6.00
60x = 600 1+ 5.00 = 6.00
x = 10 6.00 = 6.00
+ 6.00
2(.25x) = quarters---/
.10x + 2(.25x) =6.00 .10(10) + 2(.25(10)) =6.00
10x + 50x = 600 1 + 2(2.50) = 6.00
60x = 600 1+ 5.00 = 6.00
x = 10 6.00 = 6.00