Step-by-step explanation:

I think, he made a mistake because the exponents have different values but then if you'll look at his results, he just wrote the same thing. If you want, you could post the original problem, and I'll solve it for you :)
Answer:
The answer is
and 
Step-by-step explanation:
Given:
-4x-2y=14
-10x+7y=-24
Now, to solve it by elimination:
......(1)
......(2)
So, we multiply the equation (1) by 7 we get:

And, we multiply the equation (2) by 2 we get:

Now, adding both the new equations:




<em>Dividing both the sides by -8 we get:</em>

Now, putting the value of
in equation (1):




<em>Subtracting both sides by 25 we get:</em>

<em>Dividing both sides by -2 we get:</em>

Therefore, the answer is
and 
If he ate 4 of them, but it means he ate 2/5 muffins,
4 muffins = 2/5 muffins
You substitute x muffins for how much muffins she baked in all -
2/5* x muffins = 4
2/5 multiply by 2/5 to cross it out. Do the same to the other side.
x= 4 *5/2
x = 10 muffins
So there were 10 muffins in all
Answer: 5x2^5
Step-by-step explanation: Divide 160 by 2 as many times as you can to get 80x2, 40x2x2, 20x2x2x2, 10x2x2x2x2, 5x2x2x2x2x2. Then re-write your answer so that it is 5x2^5.