A two digit number has the property that the units digit is 4 less than the tens digit and the tens digit is twice the units digit. What is the number?

84

Let's assume the tens digit is represented by 'x' and the units digit is represented by 'y'.

Given that the units digit is 4 less than the tens digit, we can write the equation:
y = x - 4

Given that the tens digit is twice the units digit, we can write the equation:
x = 2y

To find the number, we need to solve these two equations simultaneously. Let's substitute the value of x from the second equation into the first equation:

y = 2y - 4

Now, solve for y by subtracting 2y from both sides of the equation:

-y = -4

Divide both sides of the equation by -1:

y = 4

Since y represents the units digit, we have found that the units digit is 4.

Now, substitute the value of y into the second equation to find the value of x:

x = 2(4) = 8

Since x represents the tens digit, we have found that the tens digit is 8.

Therefore, the two-digit number is 84.

To solve this problem, we can set up a system of equations based on the given information.

Let's assume the tens digit is represented by 'x' and the units digit is represented by 'y.'

Based on the given information, we can write two equations:
1. The units digit is 4 less than the tens digit: y = x - 4
2. The tens digit is twice the units digit: x = 2y

Now, we can substitute the value of x from the second equation into the first equation:
y = 2y - 4

Simplifying the equation:
y = -4

Now, substitute the value of y back into the equation x = 2y:
x = 2(-4)
x = -8

Therefore, the number is -8.

BAD is correct. It is 84. If you would like to use algebra, do the following:

x:= Unit Digit Number
y:= Tens Digit Number

The units digit is 4 less than the tens digit number so We know that
x=y-4

The tens digit is twice the units digit so we know that
y=2x

Now we can take the 1st equation and substitue into the second equation, then solve for Y.
y=2x
y=2(y-4)
y=2y-8
8=y so y=8
Now, sub this back into the 1st equation
x=y-4=8-4=4
so the number is yx = 84.