rachelgreen0710
rachelgreen0710 rachelgreen0710
  • 06-11-2018
  • Mathematics
contestada

15 POINTSSSSSS!!!
The sum of three numbers is 15
The second number is 2 times the first.
The third number is 20 less than the second.
What is the third number?

Respuesta :

wegnerkolmp2741o
wegnerkolmp2741o wegnerkolmp2741o
  • 06-11-2018

x+y+z=15

y =2x

z=y-20

substitute these equations into the first

x+2x+y-20 =15

now substitute 2x in for y

x + 2x +2x-20 =15

combine like terms

5x-20 =15

add 20 to each side

5x = 35

divide by 5

x=7

y =2x

y =14

z = y-20

z=14-20

z=-6

The third number is -6


Answer Link
X8lue83rryX
X8lue83rryX X8lue83rryX
  • 06-11-2018

Answer:

a + b + c = 15

a + 2xb

2xb + -20c

For the first number, it is 7

For the second number, it is 14

For the third number, it is -6

MATH CHECK:

14 - 20 = (-6)

14 + (-6) = 8

8 + 7 = 15

THIRD NUMBER = (-6)


Answer Link

Otras preguntas

The price per 100 pounds is $35.00. What would be the cost for the 1500 pounds
The lcd of 3/5, 5/16, 6/20
What’s the value? 20, 32, or 41?
What are some statements you could make to persuade someone who has engaged in risk behaviors to get tested for HIV?
What instrument made the discovery of bacteria possible?
Find the velocity of a runner that complete 400 meters in 56 seconds
Which of these is part of the natural world? A. Traffic jams B. Local weather C. Soccer games D. House construction
3a to the power 4 minus 6a to the power 2plus 9ab to the power 2
describe the two waves of U.S. immigration in the mid - 1800s
What factor prevents cells from becoming the size of giant blobs that consumes city blocks?
good job