Question

If the difference of a number and four is doubled the result is 1/4 less than the number

Answer 1

Answer:31/4 = 7.75

Explanation:

Let the number be x

the difference of a number and four is doubled. This means 2( x-4)

The result is 1/4 less than the number. This means x-1/4

Equating both, we have

2(x-4)/= x - 1/4= (4x-)/4

2x - 8 = (4x-1)/4

Cross multiply

4(2x-8) = 4x-1

8x -32= 4x-1

8x - 4x = -1+32

4x = 31

x = 31/4

=7.75

Check

2x - 8 = (4x-1)/4

2× 7.75 -8 =( 4×7.75-1)/4

7.5 = 30/4 = 7.5

Answer 2

The correct answer is 6.4. Please see below.

Explanation:

2(x - 4) = x - x/4

2(x - 4) = 4x/4 - x/4

2(x - 4) = 3x/4

8(x - 4) = 3x

8x - 32 = 3x

8x - 3x = 32

5x = 32

x = 32/5

x = 6.4

Proof replacing x by 6.4

2 (6.4 - 4) = 6.4 - 6.4/4

2 (2.4) = 6.4 - 1.6

4.8 = 4.8