Question

what is the least common denominater of 5/12 and -9/16

Answer 1

one way to do this is the first multiply the denominators
12 * 16 = 192
this is acommon denominator but it might not be the least common denominator

Answer 2

try dividing it by 2 and see if 12 and 16 are factors of the result

Answer 3

192 = 96
now is this a common denominator of 12 and 16?

Answer 4

96 / 12 = ?
96 / 16 = ?

Answer 5

are the 2 results whole numbers?

Answer 6

ya

Answer 7

right
so 192 is not the LCD because 96 is a common denominator
Now repeat what we did with 96;

96 / 2 = 48

does 12 and 16 divide exactly into 48?

Answer 8

ya thanks

Answer 9

well we are not sure if 48 is the LCD yet because we have to try out 48/2 = 24

now is 24 the LCD?

does 12 and 16 divide into 24?

Answer 10

no only 12

Answer 11

24 /12 = 2 but 16 does not divide into it

so we now know that the LCD of 12 and 16 is 48

Answer 12

We can use prime factorization
12 = 2 x 2 x 3
16= 2 x 2 x 2 x 2
Since they have two pairs of two that overlap we use them each pair once so we get
2 x 2 x 2 x 2 x 3 = 48

Answer 13

can you help whith one more

Answer 14

yes that's another method . This method is best for very large numbers.

Answer 15

please post it separately

Answer 16

which pair of fractions is equivalent to this pair 3/5 and 2/7 options a. 21/35 and 10/35
B. 10/35 and 7/35
c. 24/35 and 12/35
d. 7/35 and 5/35

Answer 17

multiply 3/5 and 2/7 by 7/7.
Basically what you are doing is multiplying by 1 so the 2 values are retained but the denominator becomes 35