Question

The sum of 3 number is 20. The second number is 4 times the first, and the sum of the first and third is 8. Find the numbers.

Answer 1

a+b+c=20
b=4a
a+c=8

The first equation minus the second equation gives you b=12
Plugging that into the second equation then gives you a=3
Plugging into the third equation gives you c=5

Answer 2

like your steps

Answer 3

i meant first minus third in the first step. but thanks :)

Answer 4

can you show me your steps though @timeparadox

Answer 5

like how i came up with the equations, or after that?

Answer 6

like your explaining and your steps on how you got your answer

Answer 7

ok i'll try to go into more detail:
assume that your three numbers are a, b, and c. they add up to 20; therefore, a+b+c=20.
second number is 4 times the first; therefore, b=4*a
first plus third is 8; therefore, a+c=8

now you can subtract the first and third equations:


plugging that into the second equation for b, 12=4*a. therefore, 12/4=a=3
plugging that into the third equation means 3+c=8
c=8-3=5

hope that helped!