Question

Find the simplified form of the expression. Give your answer in scientific notation.
(5*10^6)(3*10^5)
A) 1.5*10^11
B) 1.5*10^13
C) 15*10^11
D) 1.5*10^10

Answer 1

\[(5\times10^6)(3\times10^5)\\
= (5\times3)\times10^{6+5}\\
= \]
what do you get?

Answer 2

C

Answer 3

NB: a number in scientific notation has only digit before the decimal place.

Answer 4

A

Answer 5

\[(5\times10^6)(3\times10^5)\\
= (5\times3)\times10^{6+5}\\
= 15\times10^{11}\\
= \frac{15}{10}\times10^{11+1}\\
= %1.5\times10^{12}
\]

Answer 6

so it's not c because it would be two numbers before the decimal

Answer 7

Right?

Answer 8

right, (C is equal to the product, but it is not correct scientific notation)

Answer 9

B because of 12?

Answer 10

where is the 12?

Answer 11

The exponent you put sais 11+1

Answer 12

This is so hard haha

Answer 13

i dont see a ...10^12 option in the options above

Answer 14

Ohhh sorry that 13 is supposed to be 12

Answer 15

that makes sense then.

Answer 16

Ok can u help me on one more please?

Answer 17

Sure.

Answer 18

(4*10^10)(9*10^-5)

Answer 19

Same question as the first one

Answer 20

\[(4\times10^{10})(9\times10^{-5})\\
= (4\times9)\times 10^{10-5}\\
= \]
what do you get this time?

Answer 21

36*10^5?

Answer 22

yeah, now just get it to be a single digit before the decimal point

Answer 23

(divide 36 by 10) and (multiply 10^5 by 10)

Answer 24

what does it become?

Answer 25

3.6*10

Answer 26

3.6*10^?

Answer 27

But when I multiply I get 1000 and that's not one of my choices

Answer 28

10^5 * 10 = 10^(5+1)

Answer 29

ohhh so 3.6*10^6

Answer 30

\[\color{red}\checkmark\]

Answer 31

great work