The general idea is to solve one of the equations for one variable - in terms of the other variable or variables. Then you can substitute the entire expression into another equation or other equations; as a result, if it works you should end up having one less equation, with one less variable.
isolate
You use substitution when you can solve for one variable in terms of the others. By substituting, you remove one variable from the equation, which can then be solved. Once you solve for one variable, you can use substitution to find the other.
There isn't a universal way to do this, just like there isn't a universal way to solve nonlinear equations in one variable. A good place to start, however, would be to attempt to solve an equation for one of the variables, in terms of the other two. If you substitute that into the other equations, you will then have a system of two equations in two variables. Do this again, and you'll have a single variable equation that you'll hopefully know how to solve.
In a nonlinear equation, each variable must only have one solution.
substitution
Isolating a variable in one of the equations.
The first step is usually to solve one of the equations for one of the variables.Once you have done this, you can replace the right side of this equation for the variable, in one of the other equations.
isolate
You use substitution when you can solve for one variable in terms of the others. By substituting, you remove one variable from the equation, which can then be solved. Once you solve for one variable, you can use substitution to find the other.
There isn't a universal way to do this, just like there isn't a universal way to solve nonlinear equations in one variable. A good place to start, however, would be to attempt to solve an equation for one of the variables, in terms of the other two. If you substitute that into the other equations, you will then have a system of two equations in two variables. Do this again, and you'll have a single variable equation that you'll hopefully know how to solve.
Assuming the simplest case of two equations in two variable: solve one of the equations for one of the variables. Substitute the value found for the variable in all places in which the variable appears in the second equation. Solve the resulting equation. This will give you the value of one of the variables. Finally, replace this value in one of the original equations, and solve, to find the other variable.
In a nonlinear equation, each variable must only have one solution.
True. To solve a three variable system of equations you can use a combination of the elimination and substitution methods.
A system of equations is two or more equations that share at least one variable. Once you have determined your equations, solve for one of the variables and substitute in that solution to the other equation.
substitution
All equations for which the greatest power of its variable is 1, and that have no absolute value signs surrounding the variable, is linear. Therefore, yes, your problem is linear.
You plug in what the variable is equal to for that variable then you will be able to finish the problem