2x+15
2x+3
2n
It is simply: 2x
(10)(2x)
3 x 2 = 6
2x+3
The algebraic expression is 2m+6
2n
2b
2z
It is simply: 2x
If you mean 2n+4, or 2n-4, that already is an algebraic expression. The idea might be to put it into words. 2n+4 is twice n, increased by 4. Notice you need a comma because if you write twice n increased by 4 this is 2(n+4)
(10)(2x)
3 x 2 = 6
(2x)+3
p+2d
2X-6