contestada

The owner of a store displays a large jar of nickel and dimes and offers the value of the coins to the person who guesses how many dimes there are. If there are 1130 coins valued at 100%, how many dimes are there?

Respuesta :

Piinoy
n = nickels; $0.05
d = dimes; $0.10

[tex] \left \{ {{n + d = 1130} \atop {.05n + .1d = 100}} \right. [/tex]

n + d = 1130
Subtract n from both sides.
d = -n + 1130

Input d into the other equation.

.05n + .1(-n + 1130) = 100
.05n - .1n + 113 = 100
-.05n + 113 = 100
Subtract 113 from both sides.
-.05n = -13
Divide both sides by -.05.
n = 260

Input n into the equation we changed earlier.

d = -260 + 1130
d = 870

There were 870 dimes and 260 nickels.

Otras preguntas