posted by Margie on .
Solve the system of equations using the Addition method.
2a + 3b = -1
3a + 5b = -2
Roger's answer below is correct. If you don't understand it, please try and tell us what you don't understand.
He makes it sound so strange can you ask him to explain in an easier way?
What Roger showed you is this:
When you have 2 equations with 2 "unknowns" (in this case, a and b are unknowns), you have to make one of the unknowns go away. So, you have to figure out how to make one of the unkowns go away. Let's pick the a. How do you make the a's go away? If you add the 2 equations together, you see that the a's don't go away, it leaves you with 5a. If you subtract the bottom equation from the top, you see that the e's still don't go away, because that leaves you with -a. So, the only way to make the a's go away is to multiply the top equation by -3, and the bottom equation by 2. When you do this, you get -6a in the top equation, and 6a in the bottom. Then, when you add the equations together, the a's go away! Now you're just left with the b's to deal with.
Does this make sense??
YES!!!Thank you,you make sense.