Ok I got anther question what is 10 times 4 my brother says it is 20 but it is 40 who is correct I no I am so who ever answers get 10 points

4x 10 =40

10

10

10

+10

40

40

Step-by-step explanation:

We are attempting to show that ab=ba, where a and b are non-negative integers. Let’s introduce a new equivalence, b+e=a (i.e. e is defined as the difference between a and b; note that if e=0 then the proof becomes trivial. Also note that we assume a≥b; this does not affect our result as the variables are symmetrical). Now we write:

1) ab=∑ai=ib

This is nothing more than stating the definition of b multiplied by a, ie b summed a times. We can also write:

2) ba=b(b+e)

since b+e=a, by our own definition. We now try to show that equation (2) can be rewritten in the form of equation (1). We expand on equation (2) by writing:

3) b(b+e)=∑bi=1(b+e)

This is very similar to what we did regarding equation (1), ie b(b+e) is just (b+e) summed b times. Using some properties of addition, we can transform the right hand side of (3) to read:

4) ∑bi=1(b+e)=∑bi=1b+∑bi=1e

Now what we are going to do is assume the very thing we set out to prove! That is usually a big no-no unless you are using induction, which is basically where this is going.

5) Assume: ∑bi=1e=∑ei=1b

We now substitute (5) back into (4) and proceed:

6) ∑bi=1(b+e)=∑bi=1b+∑ei=1b

The right hand side of (6) can be simplified:

7) ∑bi=1b+∑ei=1b=∑b+ei=1b

Finally, we make use of the fact that b+e=a:

8) ∑b+ei=1b=∑ai=1b

Comparing (8) to (1) yields what we set out to prove:

9) ab=ba

b

step-by-step explanation:

your answer would be 12