Answer:
[tex]-\dfrac{3}{2}[/tex]
C is correct.
Step-by-step explanation:
Given: System of equation
[tex]9x+\frac{3}{4}y=6[/tex]
[tex]2x+\frac{1}{2}y=9[/tex]
We have to solve system of equation by eliminating y
So, first we will make the coefficient of y same with opposite sign.
Coefficient of y in first equation 3/4
Coefficient of y in 2nd equation 1/2
[tex]LCM \ of\ \frac{3}{4}\ and\ \frac{1}{2}=\frac{3}{2}[/tex]
Multiply second equation by -3/2 to make coefficient of y same
[tex]-\frac{3}{2}\cdot 2x-\frac{3}{2}\cdot \frac{1}{2}y=-\frac{3}{2}\cdot 9[/tex]
[tex]-3x-\frac{3}{4}y=-\frac{27}{2}[/tex]
[tex]9x+\frac{3}{4}y=6[/tex]
Add both equation and eliminate y
[tex]-3x+9x=-\frac{27}{2}+6[/tex]
[tex]6x=-\frac{15}{2}[/tex]
[tex]x=-\frac{5}{4}[/tex]
Hence, We multiply by -3/2 to eliminate y and solve the system of equation.
