Let's assume
first number is x
second number is y
we are given
Twice the first number minus the second number equals 18
so, we get first equation as
[tex] 2x-y=18 [/tex]
second equation is
Twice the second number minus the first number equals 9
[tex] 2y-x=9 [/tex]
we can solve for y from first equation and plug that in second equation
[tex] y=2x-18 [/tex]
now, we can plug
[tex] 2(2x-18)-x=9 [/tex]
[tex] 4x-36-x=9 [/tex]
[tex] 3x=45 [/tex]
[tex] x=15 [/tex]
now, we can find y
[tex] y=2*15-18 [/tex]
[tex] y=12 [/tex]
so,
first number is 15
second number is 12..........Answer
Let us suppose the numbers first one is x and second is y
twice the first number - second number = 2x - y =18 -------------( equation 1 )
twice the second number - first number = 2y - x = 9 ------------( equation 2)
let us substitution method for solving these two linear equations .
first equation says 2x- y =18
OR 2x - 18 = y
let us use this value of y in second equation .
second equation is 2y - x = 9
this becomes : 2 ( 2x-18 ) - x = 9
4x - 36 - x = 9
3x = 9 +36
3x = 45
x= 45/3= 15
so y= 2x- 18 = 2( 15) -18 = (30 ) -1 8 = 12
Answer : numbers are 15 and 12
