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:
600
Step-by-step explanation:
x+2x=1800
3x=1800
x=600
Answer:
1. 15x^7y^2 + 4x^3 => x^3(15x^4y^2 + 4)
2. 15x^7y^2 + 3x => 3x(5x^6y^2 + 1)
3. 15x^7y^2 + 6xy => 3xy(5x^6y + 2)
4. 15x^7 + 10y^2 => 5(3x^7 + 2y^2)
Step-by-step explanation:
To obtain the answer to the question, first let us factorise each expression. This is illustrated below:
1. 15x^7y^2 + 4x^3
Common factor is x^3, therefore the expression is written as:
x^3(15x^4y^2 + 4)
2. 15x^7y^2 + 3x
Common factor is 3x, therefore the expression is written as:
3x(5x^6y^2 + 1)
3. 15x^7y^2 + 6xy
Common factor is 3xy, therefore the expression is written as:
3xy(5x^6y + 2)
4. 15x^7 + 10y^2
Common factor is 5, therefore the expression can be written as:
5(3x^7 + 2y^2)
