a. The first variable is x and the second variable is y.
b. The equations are 
and 
Step-by-step explanation:
Step 1:
The first step is to define the variables. The variables can be any two symbols, letters, characters, etc.
Here let the first variable be x and the let the second variable be y.
So the variables are defined as x and y.
Step 2:
The sum of the given variables is 12.
The first variable + the second variable = 12,
The difference between the two variables is 4.
The first variable - the second variable = 4.
Step 3:
If we add both the equations we get, 
and 
x = 8 and y = 4.
Answer:
no solution
Step-by-step explanation:
For getting the nature of solution of the quadratic equation of the form:
ax² + bx + c = 0
We need to find Discriminant which is:
Discriminant (D) = b² - 4ac
- If D < 0, there is no solution of equation.
- If D = 0, there are two equal and real solution of equation
- If D < 0, there are two real and distinct solution of equation
Here we have equation is:
2x² - 9x + 12 = 0
∴ a=2, b = -9, c = 12
⇒ D = 81 - 4 × 2 × 12 = -16 < 0
Hence, there is no solution of given equation.
Answer:
21:50
Step-by-step explanation:
We need to find the ratio of 420 m to 1 km.
We know that,
1 km = 1000 m
So,
The ratio becomes,
So, the required ratio is 21:50.
1/12 is 10/120 is simplest form
