The sum of three numbers is 85. The first number is 5 more than the second. The third number is 3 times the first. What are the numbers?

2 Answers
Apr 22, 2018

Algebra

Explanation:

Let #x# be first number. Second number will be #x-5#. Third number will be #3x#. Add these numbers and you will get #5x-5=85# which equals to #5x = 90# and hence #x=18#

Apr 22, 2018

#18, 13, 54#

Explanation:

Let #x, y, z# be the 3 numbers:
#x+y+z= 85#
#x= y+5#
#z= 3x#

We can substitute the second and third equation for #y# and #z# into the first equation:
#y=x-5#
#z=3x#

So:
#x+(x-5)+(3x)= 85#
#5x-5=85#
#5x=90#
#x=18#

So:
#y=18-5= 13#
#z= 3(18)= 54#