How do you write a system of linear equations in two variables? Explain this in words and by using mathematical notation in an equation.

You need to have two ways the variables are related. Take a look at some of the coin problems, mixture problems, tickets sold problems, etc. Do a search in the box at the top right and I'm sure you will see how they are done.

For example, if you have 7 coins (dimes and quarters) which add up to $1.15, then

d+q = 7
10d+25q = 115

To write a system of linear equations in two variables, you need to consider two equations that describe a relationship between the two variables. Let's use the variables x and y as an example.

In words, you need to find two equations that represent two lines. These lines can intersect, be parallel, or overlap each other. Each equation defines a line and indicates the relationship between x and y values.

For mathematical notation, each equation follows the form: Ax + By = C, where A, B, and C are constants.

Here is an example of two equations in a system:

Equation 1: 2x - 3y = 5
Equation 2: 4x + y = 10

In this example, Equation 1 represents a line where the coefficient of x is 2, the coefficient of y is -3, and the constant term is 5. Similarly, Equation 2 represents a line where the coefficient of x is 4, the coefficient of y is 1, and the constant term is 10.

To solve this system of equations, you can use various methods such as substitution, elimination, or graphing, depending on the complexity and preferences.