The Lang of algebra

Question

The sum of twice a number and 5 is the difference between the number and 4.

Answer 1

2x+5 = x-4

2x-x = -4-5

x =-9

the number is -9

or you could interpret the statement to mean

2x+5 =lx-4l = the absolute value of x-4

then

2x+5 = x-4 or -(x-4) = 4-x

2x+5 = 4-x

3x =-1

x =-1/3 or -9