Scientific Notation is a way to represent very large or very less real number into easier way so that we may able to use them into our calculations.
It consist of two part a part containing the real number in decimals and the other part which is multiplied to the first part is in the form of 10 raise to some power. this exponent can be either positive or negative If it is positive the complete number is greater than one and if the exponent is negative the number is less than one.
5x 2nd power -(-4x 2nd power) makes it a positive which is 9x 2nd power then 9x 2nd power +(-3x 2nd power) which + and - make it 9x 2nd power-3x 2nd power which equals 6x 2nd power. The only answer choice with 6x 2nd power is C.
