Why we not add " s " with " km " when the distance is more than 1 e.g; 120 km ?

1. Why (-) × (+) = (-)? OR 2. Why (-) × (-) = (+)?

1.  Why (-) × (+) = (-)?

                OR

2.  Why (-) × (-) = (+)?

Here is a proof of the above two questions by using distributive law.

Consider question 1, we want two prove why (-) × (+) = (-)? For this purpose we will take two digits e.g. 2 and -3.

Now our task is to prove (2) (-3) = -6

We know that

(2)(0) = 0

= (2) (-3+3) = 0

= (2) (-3) + (2) (3) = 0

= (2) (-3) + 6 = 0

This equation will be right only if we put -6 in the place of (2) (-3) e.g.

-6+6 = 0 hence proved that (2) (-3) = -6

Now consider question 2. We want to prove why (-) × (-) = +

We take another example again e.g. (-2) (-3) = 6

Our task is to prove (-2) (-3) = 6. Here we will use distributive property again.

We know that

(-2)(0) = 0

= (-2) (-3+3) = 0

= (-2) (-3) + (-2) (3) = 0

We have already proved that (-2) (3) = -6 in the 1^st question, so we will put here -6 in place of (-2) (3), e.g.

= (-2) (-3) + (-6) = 0

The above will be true only if we put 6 in the place of (-2) (-3), e.g.

= (6) + (-6) = 0 hence proved that (-2) (-3) = 6

For any objection or suggestion please contact freely: Saleemafridi.55@gmail.com

Why anything to the power zero e.g. X^0 is equal to 1?

Why anything to the power zero e.g. X⁰ is equal to 1?

X⁰

We can also write it as;

X⁰ = X^1-1

X⁰ = X¹ × X^-1 [According to the laws of power]

X⁰

 = X¹ / X¹

= X¹ / X¹   = 1

So it is proved that anything to the zero is equal to 1.

For any objection or suggestion please contact freely: Saleemafridi.55@gmail.com