How many numbers are 10 units from 0 on the number line? Type your answer as a numeral.

There are two numbers 10 units from zero on the number line. These are 10 and -10.

Step-by-step explanation:

On a number line, if you move a pointer ten units right and left you will land on 10 and -10.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".