Equations with Two Variables
You have seen equations containing one unknown, x,
and you can solve such an equation to find the value of the unkown.
Now let's take a look at equations involving two unknowns
x and y. Here is an example:
x − y = 0
What values for x and y satisfy this equation?
Well, any values as long as their difference is zero. In other words,
as long as y = x. Thus, x=1, y=1 is a solution,
so is x=2, y=2 and so on. Here is another equation
2 x − 3 y = 0
If we give x some specific value, say 7, we can ask what is the corresponding value of y. Let's experiment with this equation.
Pick a value, any small integer value will do, that you wish to substitute for
xin the above equation:x =And it is displayed here. Numbers are rounded to the nearest hundredth.
You can solve this equation in a sequence of steps just as before, by adding, subtracting, multiplying and dividing both sides with a number. The trick is to come up with the number and operation to perform in each step to obtain the final equation y = the answer.
Enter a number and click a button and the operation will be applied to both sides of your equation:
Go back to step 1 and try to solve for
yagain with a different value forx.