Adding the 2 equations, term by term on both sides, will eliminate y leave an equation in x the we deserve to solve.
You are watching: The sum of two numbers is and the difference is . what are the numbers
#rArr(1)+(2)" gives"#
#(x+x)+(color(red)(-y+y))=(4+12)#
#rArr2x=16#
divide both political parties by 2
#(cancel(2) x)/cancel(2)=16/2#
#rArrx=8#
Substitute this value right into equation ( 1 ) and solve because that y
#rArr8+y=12#
#rArry=12-8=4#
#"Thus the 2 numbers are " 8" and also " 4#
Answer link
LM
Mar 19, 2017
#a=4##b=8#
Explanation:
let these 2 numbers it is in #a# and also #b#.
#a+b=12##a-b=4#
if you include the 2 equations:
#a+b=12##a-b=4#
#2a+0 = 8##2a = 8#
divide through #2#:#a = 4#
substitute:#a+b = 12##4+b=12##b=12-4##=8#
#a=4##b=8#
#8+4=12##8-4=4#
Answer attach
David Drayer · EZ as pi
Mar 19, 2017
There are two number so you need two equations. Settle for one variable ( number) and then substitute and also solve because that the other.
#x = 8 and y = 4#
Explanation:
Let #x# same one number and also #y# the other number.
One equation would certainly be the sum of the numbers.
#x + y = 12#
the various other equation would certainly be the distinction of the 2 numbers
#x-y = 4" "#
Now add the two equations
#x +y = 12 " " and also " "x -y = 4" "#(adding #+ y and also -y = 0#)
so #2x = 16" "# currently divide both sides by 2
# (2x)/2 = 16/2" "# This provides
#x = 8# currently substitute x right into one of the equations and solve because that y
#8 + y =12" "# subtract 8 indigenous both political parties
# 8 -8 +y = 12 -8 " "# This gives
#y = 4" "# put values into the second equation to inspect
#8 -4 = 4 #
#4 = 4" "# examine
#x = 8 and also y = 4#
Answer attach
EZ as pi
Mar 22, 2017
The numbers room #4 and also 8#
Explanation:
Questions which involve 2 or much more numbers can be done utilizing one variable to specify them all.
Let the smaller sized number it is in #color(red)(x)#.
See more: Where Did You Just Assume My Gender ? ’ Comment F***Ing Sucks&Ndash Spectrum Outfitters
The difference between the number is #4#.
The various other number is #color(blue)(x+4)#
Their sum is #12#
#color(red)(x) +color(blue)(x+4) =12#
#2x = 12-4#
#2x = 8#
#x =4#
#:. X+4 = 8#
The numbers space #4 and 8#
Answer attach
Related concerns
view all inquiries in Problem-Solving Models
affect of this question
127449 views approximately the civilization
You can reuse this answer an imaginative Commons patent