Is 25 x 10 to the power of 0 in scientific notation? If not, explain. Use pencil and paper. Explain why 10 is used as the base in the second scientific notation factor.

a) Scientific notation is written as a unit digit, that can have other digits after the decimal place, multiplied by 10 to the power of n, where n can be any integer number.

Then 25x10^0 is not scientific notation, because there are two digits at the left of the decimal point.

The scientific notation would be:

2.5x10^1

b) Why is this useful?

Because we divide all our measures in powers of 10.

For example, you know that 1 meter  = 100c

But we can also write this as:

1m = 1.0*10^3 cm.

The use of scientific notation comes useful because we can have a fast read of the dimensions of our measure, and in another hand, is way easier work with the 10 as a base when we solve equations.

hello from mrbilldoesmath!

answer:

x - 3

discussion:

x^2 - 9 = (x-3) (x+3)   so

(x^2-9)/ (x + 3) = x-3

you,

mrb