I won't answer them all for you (don't want to cheat - need to learn something).
But for the first one given:
<span>-2x-9y=-25
-4x-9y=-23
you set up either x or y (which ever one you want to eliminate) so that one of them cancels.
So this one is easy - you just have to multiply an entire row by negative (doesn't matter which one) - so that the y's will be + and -
Since they're both 9 and they're subracting NOW - you can eliminate the y value. Now add/subtract the x's. So it'd be -2 or 2 depending on how you eliminated y. Then add the number outside of the = sign. Now just solve for x. After that plug in whatever you got for x into both of the rows. Then find the y value.
Hopefully this wasn't confusing -- reply if it is and I will try to simplify. I can give you contact if you need help with the rest
Good luck!</span>
Answer:
Combine like terms for the than you do to other side the multiply last for least you divide both sides
Step-by-step explanation:
Answer:
(-2, -3)
Step-by-step explanation:
We assume your system of equations is ...
You can subtract the second equation from the first to get
... (2x -y) -(2x -4y) = (-1) -(8)
... 3y = -9 . . . . . collect terms
... y = -3 . . . . . . divide by 3 . . . . this is sufficient to identify the correct answer
Substituting into the first equation, we have ...
... 2x -(-3) = -1
... 2x = -4 . . . . . add -3
... x = -2 . . . . . . .divide by 2
Now, we're sure the answer is (x, y) = (-2, -3).
