A teacher wrote the equation 3y + 12 = 6x on the board. For what value of b would the additional equation 2y = 4x + b form a system of linear equations with infinitely many solutions?

b = –8

b = –4

b = 2

b = 6

Verified Answer :

Answer: First option.

Step-by-step explanation:

The equation of the line in Slope-Intercept form is:

\(y=mx+b\)

Where "m" is the slope of the line and "b" is the y-intercept

We need to write each equation in Slope-Intercept form:

First equation

\(3y + 12 = 6x\\\\3y=6x-12\\\\y=2x-4\)

Second equation

\(2y = 4x + b \\\\y=2x+\frac{b}{2}\)

Since, by definition, a system of linear equations has infinitely many solutions when the lines are the same, we can say that:

\(y=y\\\\2x-4=2x+\frac{b}{2}\)

Then, solving for "b", we get:

\(-4=\frac{b}{2}\\\\(-4)(2)=b\\\\b=-8\)

Answer:

-8

Step-by-step explanation:

Just took test lol