Question

how do you multiply rational numbers

Answer 1

To multiply the rational numbers p/q and r/s, simply multiply the corresponding numerators and denominators (and simplify if possible)


So (p/q)*(r/s) = (p*r)/(q*s)

Answer 2

For example, to multiply 2/5 and 3/7, multiply the corresponding numerators (2 and 3) and multiply the corresponding denominators (5 and 7)

So

(2/5)*(3/7) = (2*3)/(5*7) = 6/35

Answer 3

what if its a negative times positive ?

Answer 4

the answer will be negative

Answer 5

(negative)*(positive) = negative

Answer 6

so in the problem i dont evan wory about the negative and positive sign till the answer ?

Answer 7

yes

Answer 8

just work with the numbers themselves and worry about the sign later (but don't forget it)

Answer 9

okay , do you think you can help me with my fist problem so i can make sure i got this ?

Answer 10

sure, what is it

Answer 11

3/8 (-7/10) , it says mutilpy and then put in simpliest form

Answer 12

ok, what did you get

Answer 13

i got -21/80 , but i dont think thats right.

Answer 14

that's correct

Answer 15

and you cannot reduce that

Answer 16

on this othe section it just says multiply , but no simplify and the poblem is -2.1(-7)... && i got ..

Answer 17

actually i dont know how to evan do this one at all.

Answer 18

just multiply without the decimal:

-21 times -7 = 147


Now reintroduce the decimal and a 0 at the very end to get 147.0

and move that decimal one spot to the left to get the final answer of 14.7

Answer 19

I moved the decimal one spot to the left because the decimal in -2.1 has been moved one place to the left (to go from -21.0 to -2.1)

Answer 20

oh okay , also sorry to be a pain in the butt , but ca you help me on these 2 word problems too ?

Answer 21

sure

Answer 22

* Tran jogs 3/4 miles a day. What is the total distance Tran jogs in 6 days.
*There was 3/4 of a pizza left over from a family gathering. The next day , Tina ate 1/2 of what was left. How much of the pizza did Tina eat.

Answer 23

ok let's take them one at a time

Answer 24

* Tran jogs 3/4 miles a day. What is the total distance Tran jogs in 6 days

Answer 25

To find the answer, we simply multiply the number of miles jogged per day by the number of days Tran jogs


So (3/4)*(6) = (3/4)*(6/1) = (3*6)/(4*1) = 18/4 = 9/2


So (3/4)*(6) = 9/2


Now convert 9/2 to the mixed number 4 1/2


So Tran jogged 4 1/2 (four and a half) miles

Answer 26

Does that make sense?