i am a two digit number above 50. the sum of my digits is 12. and the difference of my digits is 4. who am i?
let the tens digit be x
let the unit digit be y
x+y = 12
x-y = 4
add them
2x = 16
x = 8
y = 4
the number is 84
Since the choices were quite limited, (x = 5,6,7,8,or9 )
it would have been just as fast to "guess" at the solution
84
Let both the numbers be 10x and y
As the question says
x+y=12
x-y=4
Now add both 12 and 4 (12+4=16)
2x=16 (divide: 16÷2=8)
x=8
Now subtract: (16-8=4)
y=4
Therefore 10x and y = (10*8=80) 80+4=84
Now to check the answer:
8+4=12
8-4=4
It is above 50
So the answer is correct
84
To find the two-digit number that meets the given criteria, we can use algebraic reasoning. Let's assume the first digit of the number is 'x', and the second digit is 'y'.
According to the given information, we know that the number is greater than 50 (meaning x > 5) and the sum of the digits is 12 (x + y = 12). Additionally, we're told that the difference between the digits is 4 (x - y = 4).
We can now solve these two equations simultaneously to find the value of x and y. Here's how:
From the equation x + y = 12, we can isolate x by subtracting y from both sides:
x = 12 - y
Substituting this value of x in the second equation, we get:
(12 - y) - y = 4
12 - 2y = 4
Now, solve for y:
12 - 4 = 2y
8 = 2y
y = 4
Substitute the value of y back into the equation for x:
x = 12 - 4
x = 8
So, the two-digit number that meets the given criteria is 84.