Answer:

Step-by-step explanation:


Divide both sides by 4:


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:
GCF: 20
Step-by-step explanation:
The thing you want to do is factor both numbers down to their lowest primes.
40:2 * 2 * 2 * 5
60:2 * 2 * 5 * 3
Now underline what is in both sets of primes. I'll bold them. The number that is bolded comes from 2 * 2 * 5 which is 20
The highest common factor is 20
Answer:
1,000,000
Step-by-step explanation: