Rewrite the first fraction using the LCD of 7 and 21.

the lcd of 7 and 21 is 21

Step-by-step explanation:

You need to know the least common denominator (LCD) of 21 and 7 if you want to add or subtract two fractions with 21 and 7 as denominators.

The least common denominator, also called lowest common denominator (LCD), of 21 and 7 is 21.

Here is a math problem example where you need to know the LCD of 21 and 7 to solve:

3/21 + 2/7 = ?

Step 1) Take the LCD and divide each denominator by it as follows:

21/21 = 1

21/7 = 3

Step 2) Multiply each nominator with the respective answers from Step 1:

3 x 1 = 3

2 x 3 = 6

Step 3) Put it all together to solve the problem:

3/21 + 6/21 = 9/21

= 3/21 + 2/7 = 9/21

It's that easy! Once again, the lowest common denominator (LCD) of 21 and 7 is as follows:

21

the smallest possible measurement of the width is 14 feet

step-by-step explanation:

let's assume length of parallelogram is 'l'

width of parallelogram is 'w'

the perimeter of a parallelogram must be no less than 40 feet

so, we get

we are given

length of parallelogram is 6 feet

so,

l=6

we can plug it

now, we can solve for w

subtract both sides by 12

divide both sides by 2

and we get

so,

the smallest possible measurement of the width is 14 feet