| Solved by pluggable solver: Solving a linear system of equations by subsitution |
Lets start with the given system of linear equations Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to choose y. Solve for y for the first equation Which breaks down and reduces to Since y equals So when we multiply Now that we know that So this is the other answer So our solution is which can also look like ( Notice if we graph the equations (if you need help with graphing, check out this solver) we get and we can see that the two equations intersect at ( ----------------------------------------------------------------------------------------------- Check: Plug in ( Let So the solution ( Let So the solution ( Since the solution ( this verifies our answer. |
How come you haven't learned how to do these problems YET? There might have been more than 30 of these over the past few days.
Why have you chosen someone or some people on here to do your math assignments for you? All these problems are the same! Why can't you
now do them by yourself after being shown how some are done?
If you decide to do this one (considering the fact that the other person who's been solving these problems has chosen to use the most
inefficient and most time-consuming method), then ALL you need to do is the following:
1) Multiply eq (i) by 3 to form eq (iii) and then add eqs (iii) & (ii). This eliminates y and gives you the value of x
2) Substitute the value of x in any of the 2 ORIGINAL equations to find y.
That's IT. NOTHING more, NOTHING less!!