Answer:
The correct option is B. [tex]y=-3x+4 \ \text{and}\ \ 3y=-9x+12[/tex]
Step-by-step explanation:
Consider the two linear equation:
[tex]a_1x+b_1y+c_1=0\ \text{and}\ \ a_2x+b_2y+c_2=0[/tex]
The pair of linear equation has infinitely many solutions when:
[tex]\frac{a_1}{a_2}=\frac{b_1}{b_2}=\frac{c_1}{c_2}[/tex]
Now consider the option.
Option a) [tex]y=-3x+4 \ \text{and}\ \ y=-3x-4[/tex]
The above equation can be written as:
[tex]y+3x-4=0 \ \text{and}\ \ y+3x+4=0[/tex]
Therefore,
[tex]\frac{1}{1}=\frac{3}{3}\neq\frac{-4}{4}[/tex]
Thus, this pair has no solution.
Now consider the option B. [tex]y=-3x+4 \ \text{and}\ \ 3y=-9x+12[/tex]
The above equation can be written as:
[tex]y+3x-4=0 \ \text{and}\ \ 3y+9x-12=0[/tex]
Therefore,
[tex]\frac{1}{3}=\frac{3}{9}=\frac{-4}{-12}[/tex]
Thus, this pair has infinitely many solution.
Hence, the correct option is B. [tex]y=-3x+4 \ \text{and}\ \ 3y=-9x+12[/tex]
