Find the slope of the line passing through each of the following pairs of points. (−3, 9), (−3, −5) (5, 6), (3, 4) (0, 7), (0, −8) (4, 0), (−2, 8)

Look carefully at the first pair:  (−3, 9), (−3, −5)  Note that x does not change, tho' y does.  This is how we recognize a vertical line (whose slope is undefined).  The equation of this vertical line is x = -3.

Looking at the second pair:  from (3,4) to (5,6), x increases by 2 and y by 2; thus, the slope is m = rise/run = 2/2 = 1.

Third pair:  as was the case with the first pair, x does not change here, and thus the equation of this (vertical) line is x=0 (which is the y-axis).  The slope is undefined.

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".