4 yd
What is the diameter?

4

Step-by-step explanation:

   circumference: 12.56 yd

   area: 12.56 yd²

Step-by-step explanation:

The formula for circumference is ...

 C = πd

 C = (3.14)(4 yd) = 12.56 yd . . . . . . . . fill in the numbers; do the arithmetic

The circumference is 12.56 yd.

__

Since the diameter is 4 yd, the radius is half that, or 2 yd. The formula for the area is ...

 A = πr²

Fill in the numbers and do the arithmetic.

 A = (3.14)(2 yd)² = 12.56 yd²

The area is 12.56 yd².

Comment on units

In problems such as these, I find it is often useful to keep the units with the numbers. The units can be treated like any variable: multiplied, divided, measures combined by addition or subtraction of "like units".

Just as (2a)² = 2²·a² = 4a², so does (2 yd)² = 2²·yd² = 4 yd². You can be sure that if the units of the problem don't make sense, there is an error somewhere.

costs the what? what is the cost of the pants?

step-by-step explanation:

if it is $10, then the price is 14.

take 40% of the cost, and then add the cost.

40% of 10 = 4

4+10 = 14.

step-by-step explanation:

y = | -2(-2) |     →     y = | 4 |     →     y = 4       ⇒   (-2, 4)

y = | -2(-1) |     →     y = | 2 |     →       y =   2       ⇒   (-1, 2)    

y = | -2(0) |     →     y = | 0 |     →       y = 0         ⇒   (0, 0)

y = | -2(1) |   c →     y = | -2 |     →     y =   2         ⇒   (1, 2)    

y = | -2(2) |     →     y = | - 4 |     →     y =   4         ⇒   (2, 4)