Two numbers differ by 12. Twice the larger number increased by triple the smaller number, totals 104. What are the two numbers?

1 Answer
Feb 15, 2018

2 numbers differ by 12
Let... #x# be the larger number
Let..... #y# be the smaller number
Then of course smaller number subtracted by larger number would give positive difference
#x-y=12#
Add #y# to both sides
#x-cancely+cancely=12+y#
#x=12+y#.....(1)

Now, here it says twice the larger number.... means #2xxx=2x# now that is increased by(added to) triple the smaller number, means #3xxy=3y# now that is equal to #104#

jot it down in one equation
#2x+3y=104#.....(2)
Put value of #x# from equation one into equation two
#2xx(12+y)+3y=104#
Multiply
#2xx12+2xxy+3y=104#
#24+2y+3y=104#
Subtract both sides by 24 and add the #2y# and #3y#
#cancel24-cancel24+5y=104-24#
You get
#5y=80#
Transfer #5#
#y=80/5#
#color(red)(y=16#
Put value of #y# in equation one to get value of #x#
#x=12+y#
#x=12+16#
Solve
#color(red)(x=28#

Hope this helps