Question

what is 2 5/7b - 2/3

A. 2 1/7


B. 2 1/21



C. 2 3/4



D. 1 3/4

Answer 1

PLEASE HELP


I'VE USED A CALCULATOR AND IT STILL DOESN'T GET THE ANSWER RIGHT!!

Answer 2

I will medal for correct answer!

Answer 3

Is that supposed to be
\[2 \frac{5}{7} - \frac{2}{3}\]

Answer 4

yeah

Answer 5

okay, when you used a calculator, what result did you get?

Answer 6

16/21

Answer 7

okay, first convert \[2\frac{5}{7}\]to an improper fraction, what is the result?

Answer 8

if you divide 1 into 7 equal parts, how many 1/7's do you have?

Answer 9

if you divide a candy bar into 7 equal parts, you have 10 little pieces of candy bar?!?

Answer 10

don't you have 7?

Answer 11

IDK

Answer 12

that's okay, we don't need the computer, just your brain.

you have an apple. you divide it into 4 equal parts. isn't each part 1/4 of the apple?

Answer 13

lol I read your response wrong

Answer 14

okay, so if we convert 1 into 7ths, don't we have \[1 = \frac{7}{7}\]?

Answer 15

yes

Answer 16

and then if we add another \(1\), it would be \[1+1 = \frac{7}{7} + \frac{7}{7} = \frac{14}{7}\]
and then we add another \(\dfrac{5}{7}\)
\[2\frac{5}{7} = 1+1+\frac{5}{7} = \frac{7}{7}+\frac{7}{7}+\frac{5}{7} = \frac{19}{7}\]

agree, disagree?

Answer 17

agree

Answer 18

in general, if you have a mixed fraction of the form \[a\frac{b}{c}\]you convert it to an improper fraction by doing \[a\frac{b}{c} = \frac{a*c + b}{c}\]

So\[2\frac{5}7 = \frac{2*7+5}{7} = \frac{19}{7}\]

Answer 19

so now our problem looks like \[\frac{19}7 -\frac{2}3\]how do you proceed from here?

Answer 20

you find the common denominator

Answer 21

excellent. what is the common denominator you are going to use here?

Answer 22

21

Answer 23

now we're talking. what is the problem going to look like after you convert both fractions to use 21 as the denominator?

Answer 24

57/21 -14/21

Answer 25

good, so the final answer is....drumroll please...

Answer 26

43/21 or 2/21?

Answer 27

no 2 1/21

Answer 28

that's what i meant

Answer 29

got it!

Answer 30

any questions about how we did that?