Please help! I havnt this kind of math for so long?

Question

I have to do these for a paper and completley forgot how to!!

prime factorizations for 36, 100, and 2006

AND

Use the LCD to add 5/12, 1/18, and 3/28.
(what is LCD???!)

Thanks!!

Answer 1

1. Break down each number until you reach nothing but prime numbers:
36 = 6*6 or (2*3)*(2*3)
100 = 4*25 or (2*2)*(5*5)
2006 = 2*1003 or 2*(59*17)

2. LCD is least common denominator (what is the least number all these denominators can go into?)
12 = 3*2*2, 18 = 3*3*2, and 28 = 2*2*7
so the LCD is 3*2*2*3*7 or 252

Part 2 of this is converting these fractions so that they are all portions of the LCD, 756.
12 goes into 252, 21 times, so 5/12 = (5*21)/(12*21) or 105/252.
18 goes into 252, 14 times, so 1/18 = (1*14)/(18*14) or 14/252.
28 goes into 252, 9 times, so 3/28 = (3*9)/(28*9) or 27/252.

Add those all together, you get (105+14+27)/252 or 146/252.

Whew!

Answer 2

LCD = Lowest Common Denominator

Therefore you need to find a number (which will be the denominator) that 12, 18 and 28 all are able to fit in. e.g. if you had 1/2, 5/6, and 5/12; the LCD would be 12 because 2 can be multiplied by 6 to get 12, 6 can be multiplied by 2 to get 12, and 12 is already 12. In your question try taking the largest denominator (28), try multiplying it by 2, and check if the other will be able to equal that number, if not try x3 and do the same thing. Continue like that

Answer 3

The LCD is actually the smallest number that all the denominators can be multiplied into evenly. So the answer for 5/12 1/18 and 3/28 is 252, so you get:

5*21+1*14+3*9
--------------------= (105 + 14 + 27)/252 = 146/252=73/126
252

Answer 4

LCD is Lowest Common Denominator.. i.e while adding 5/12, 1/18 and 3/28, you need to find the Lowest Common number that is a multiple of 12, 18 and 28 (the denominators).

The LCD of 12, 18, 28 comes to 252 i.e 2x2x3x3x7.
Now you need to multiply the numerators of each fraction with the corresponding multiple of the denominators.. for first one.. 5x21 = 105, for the second one.. 1x14 = 14, and finally 3x9 = 27.

Adding them up gives.. (105 + 14 + 27)/252 = 146/252.

Answer 5

Break it down into all factors that are only divisible by 1, example:

36=18x2=6x3x2=3x2x3x2

LCD is lowest common denominator (lowest factor common to other denominators)

for 12=2x2x3
for 18=3x3x2

so LCD for those 2 numbers is 2

Answer 6

LCD is lowest common facter

so 5/12+1/18+3/28
=2520/6048+336/6048+648/6048
=3504/6048
=73/126 ( this is in lowest terms )
Prime Factrizations for 36 is
36/2=18
18/2=9
9/3=3
PRIME facter of 36 is 2*2*3*3
try the rest your self

Answer 7

Prime Factoization
36:2x3x3x3x3
100:2x2x5x5
2006:2x1003

Answer 8

I think prime factor is 2.take the common out it is only 2.LCD what is the full form.

Answer 9

LCD is lowest common denominator.

I THINK you make a factor tree and say

36 -> 6 x6 -> 2x3