contestada

Mildred brought 1 cent stamps,32 cent stamps, and 33 cent stamps for $21.80. The number of 1 cent stamps exceed the number of 33 cent stamps by 50. The number of 32 cents was 10 less than twice the number of 33 cents stamps. How many of each kind did she buy? Mildred brought 1 cent stamps,32 cent stamps, and 33 cent stamps for $21.80. The number of 1 cent stamps exceed the number of 33 cent stamps by 50. The number of 32 cents was 10 less than twice the number of 33 cents stamps. How many of each kind did she buy?

Respuesta :

texaschic101
x = 1 cent, y = 32 cent, and z = 33 cent

0.01x + 0.32y + 0.33z = 21.80
x = z + 50
y = 2z - 10

0.01(z + 50) + 0.32(2z - 10) + 0.33z = 21.80
0.01z + 0.5 + 0.64z - 3.20 + 0.33z = 21.80
0.98z - 2.7 = 21.8
0.98z = 21.8 + 2.7
0.98z = 24.5
z = 24.5 / 0.98
z = 25 <=== 33 cent stamps

x = z + 50
x = 25 + 50
x = 75 <=== 1 cent stamps

y = 2z - 10
y = 2(25) - 10
y = 50 - 10
y = 40 <== 32 cent stamps


 



Otras preguntas