Question

Which is true of the standard form of the equation of the line graphed?

A) The value of A can be –1 if the value of C is 3 and the value of B is 0.
B) The value of A can only be 1, the value of C can only be –3, and the value of B is 0.
C) The standard form of the equation can be shown as 3x = –9.
D) The standard form of the equation can only be x + 3 = 0.

Answer 1

Standard form of a line

• Ax+By=c

The equation of line is x=-3

• There is no y inetercept so B is 0

Then

• Ax+0=C
• Ax=C

A is 1

And

putting x=-3

• -3(1)=C
• C=-3

Option B

Answer 2

• B) The value of A can only be 1, the value of C can only be –3, and the value of B is 0.

Explanation:

The graphed line is a vertical line with the x-intercept (-3, 0).

The standard form is:

• Ax + By = C

Since the line is vertical, the value of B is zero.

The line becomes:

• Ax = C

And we see x = -3, hence A = 1, C = -3

Correct choice is B