Answer:
a. No solution, parallel lines.
b. One solution.
Step-by-step explanation:
Given the system of equations:
a. ![2x-4y=12](https://tex.z-dn.net/?f=2x-4y%3D12)
![-3x+6y=-15](https://tex.z-dn.net/?f=-3x%2B6y%3D-15)
b. ![2x-4y=12](https://tex.z-dn.net/?f=2x-4y%3D12)
![-5x+3y=10](https://tex.z-dn.net/?f=-5x%2B3y%3D10)
To give a geometric description of the given system of equations.
The geometric description of a system of equations in 2 variables mean the system of equations will represent the number of lines equal to the number of equations in the system given.
i.e.
Number of planes = Number of variables
Number of lines = Number of equations in the system.
Here, we are given 2 variables and 2 equation in each system.
So, they can be represented in the xy-coordinates plane.
And the number of solutions to the system depends on the following condition.
Let the system of equations be:
![A_1x+B_1y+C_1=0\\A_2x+B_2y+C_2=0](https://tex.z-dn.net/?f=A_1x%2BB_1y%2BC_1%3D0%5C%5CA_2x%2BB_2y%2BC_2%3D0)
1. One solution:
There will be one solution to the system of equations, If we have:
![\dfrac{A_1}{A_2}\neq\dfrac{B_1}{B_2}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%5Cneq%5Cdfrac%7BB_1%7D%7BB_2%7D)
2. Infinitely Many Solutions: (Identical lines in the system)
![\dfrac{A_1}{A_2}=\dfrac{B_1}{B_2}= \dfrac{C_1}{C_2}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%3D%5Cdfrac%7BB_1%7D%7BB_2%7D%3D%20%5Cdfrac%7BC_1%7D%7BC_2%7D)
3. No Solution:(Parallel lines)
![\dfrac{A_1}{A_2}=\dfrac{B_1}{B_2}\neq\dfrac{C_1}{C_2}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%3D%5Cdfrac%7BB_1%7D%7BB_2%7D%5Cneq%5Cdfrac%7BC_1%7D%7BC_2%7D)
Now, let us discuss the system of equations one by one:
a.
OR
OR ![-3x+6y+15=0](https://tex.z-dn.net/?f=-3x%2B6y%2B15%3D0)
![A_1 = 2, B_1 = -4, C_1 = -12\\A_2 = -3, B_2 = 6, C_2= 15](https://tex.z-dn.net/?f=A_1%20%3D%202%2C%20B_1%20%3D%20-4%2C%20C_1%20%3D%20-12%5C%5CA_2%20%3D%20-3%2C%20B_2%20%3D%206%2C%20C_2%3D%2015)
Here, the ratio:
![\dfrac{A_1}{A_2}=\dfrac{B_1}{B_2} = -\dfrac{2}{3}\\\dfrac{C_1}{C_2} = -\dfrac{4}{5}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%3D%5Cdfrac%7BB_1%7D%7BB_2%7D%20%3D%20-%5Cdfrac%7B2%7D%7B3%7D%5C%5C%5Cdfrac%7BC_1%7D%7BC_2%7D%20%3D%20-%5Cdfrac%7B4%7D%7B5%7D)
![\dfrac{A_1}{A_2}=\dfrac{B_1}{B_2}\neq\dfrac{C_1}{C_2}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%3D%5Cdfrac%7BB_1%7D%7BB_2%7D%5Cneq%5Cdfrac%7BC_1%7D%7BC_2%7D)
Therefore, no solution i.e. parallel lines.
b.
OR ![2x-4y-12=0](https://tex.z-dn.net/?f=2x-4y-12%3D0)
OR ![-5x+3y-10=0](https://tex.z-dn.net/?f=-5x%2B3y-10%3D0)
![A_1 = 2, B_1 = -4, C_1 = -12\\A_2 = -5, B_2 = 3, C_2 = -10](https://tex.z-dn.net/?f=A_1%20%3D%202%2C%20B_1%20%3D%20-4%2C%20C_1%20%3D%20-12%5C%5CA_2%20%3D%20-5%2C%20B_2%20%3D%203%2C%20C_2%20%3D%20-10)
![\dfrac{A_1}{A_2}= -\dfrac{2}{5}\\\dfrac{B_1}{B_2} = -\dfrac{4}{3}\\\dfrac{C_1}{C_2} = -\dfrac{6}{5}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%3D%20-%5Cdfrac%7B2%7D%7B5%7D%5C%5C%5Cdfrac%7BB_1%7D%7BB_2%7D%20%3D%20-%5Cdfrac%7B4%7D%7B3%7D%5C%5C%5Cdfrac%7BC_1%7D%7BC_2%7D%20%3D%20-%5Cdfrac%7B6%7D%7B5%7D)
![\dfrac{A_1}{A_2}\neq\dfrac{B_1}{B_2}](https://tex.z-dn.net/?f=%5Cdfrac%7BA_1%7D%7BA_2%7D%5Cneq%5Cdfrac%7BB_1%7D%7BB_2%7D)
So, one solution.
Kindly refer to the images attached for the graphical representation of the given system of equations.