We have
.
First let us factor the 2 to obtain,

We can now see clearly that the expression inside the parentheses is a difference of two squares.
We now write the 4 as 2². So that we obtain the expression,

Recall that

Hence our expression becomes,

Therefore, when factored completely,

There are no numbers for this, thus you will have to use the quadratic formula.
Answer:
As in 4 hours , 20 men can cut 30 trees. So, in 1 hour , 20 men can cut 30 trees / 4. So, in 6 hours, 20 men can cut 30 * 6 trees / 4 = 45 trees.
Step-by-step explanation:
done
Answer:

Step-by-step explanation:
We know that the length is four times the width, so:

We also know the area, which is 324 m². The formula for area:

Insert the known values:

Solve for w. Simplify by removing parentheses:

Divide 4 from both sides to isolate the variable:

Find the square root of both sides:

The width is 9 m.
We know the width. Now find the length by using the area formula and inserting known values:

Solve for l. Divide both sides by 9:

The length of the rectangle is 36. (You can check: 4 times 9 is 36)
Now find the perimeter:

Insert values:

The perimeter is 90 m.
Answer:

Step-by-step explanation:
When you have something like that, just think that the first number goes on top and the second number goes on bottom.