gr1lledch3esy
gr1lledch3esy gr1lledch3esy
  • 17-03-2021
  • Mathematics
contestada

Five pens and four pencils cost $2.55. But four pens and five pencils cost $2.40. How
much do the pens cost and how much do the pencils cost?

Respuesta :

pahands
pahands pahands
  • 17-03-2021

1*5=12.75

2*4=9.6

so nine pens cost 3.15

one pen will be 0.35$

so one pencil will be .20$

Answer Link
claudiaf357
claudiaf357 claudiaf357
  • 17-03-2021

Answer:

pens: $0.35, pencils: $0.20

Step-by-step explanation:

pens=x

pencils=y

5x+4y=255 --> 5x=255-4y --> x = 51 - 4y/5

4x+5y=240

4(51-4y/5) + 5y = 240

204 - 16y/5 + 5y = 240

5y - 16y/5 = 36

25y - 16y = 180

9y = 180

y = 20 cents = $0.20

x = 51 - 4(20)/5

x = 51 - 16

x = 35 cents = $0.35

Answer Link

Otras preguntas

Which detail from the article illustrates that not all of the Marfa lights are caused by headlights from a nearby highway?
Values and norms are the same all around the world
What do the arrows show about the movement of the winds in this pressure center? What else indicates wind direction?
dknkfhnf;kvnkvnfjnfekfnekne
Why is it important to do clinical nurse specialist as a career
two investments totaling $28,000 produce annual income of $1435. One investment yields 9% per year, while the other yields 2% per year. How much is invested at
if 5x is the average of two numbers and one of the numbers is 3, what is the other number?
5t+3t=100 what is t?
Mga Katangian ng epiko
Mark wants to find the area of a circle with a diameter of 8 cm. Which expressions can he use to find the area of the circle in square centimeters? Choose all t