In algebra 2x mean what BTW x = 4

Question

I have a problem that says "Evaluate (2x + 4) – (3x + 6) when x = 4." and the 2x IDK what it means.

Answer 1

Two ways to do this.

(1) (2x+4)-(3x+6); evaluate the contents of the parentheses after putting x=4:

2x+4=2×4+4=8+4=12; 3x+6=3×4+6=12+6=18;

so (2x+4)-(3x+6)=12-18=-6.

(2) (2x+4)-(3x+6)=2x+4-3x-6=2x-3x+4-6=-x-2.

When x=4, -x-2=-4-2=-6.

Either way is valid.