What is the distance between y = 3x + 9 and y = 3x - 4?

  A.  4.11 units

Step-by-step explanation:

It can be convenient to put one of these equations into general form, then use the formula for the distance from a point to a line.

In general form, the first equation is ...

  3x -y +9 = 0

So, the distance from a point to that line is ...

  ax +by +c = 0 . . . . . . equation of a line

  d = |ax +by +c|/√(a^2+b^2) . . . corresponding distance formula

  d = |3x -y +9|/√(3^2 +(-1)^2)

Using the y-intercept of the other line as the point of interest, we find its distance to the first line to be ...

  d = |3(0) -(-4)+9|/√10 = 13/√10 ≈ 4.11

The distance between the lines is about 4.11 units.

_____

Unless the lines are vertical or horizontal, you know the distance will be less than the difference between the x- or y- intercepts. Here, the y-intercepts are separated by 9-(-4) = 13 units. The x-intercepts are -3 and 4/3, so are separated by 4 1/3 units. Any answer choice larger than 4.33 cannot be correct.

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".

use google you idiot omg you're so annoying

step-by-step explanation: