Answer:
Step 2 has the error
1. The whole number (20) was left out
2. Adding different signs, we subtract and retain the sign from the larger number
Correction:
Step 2: 20 - 17x = 34x + 60
Step 3: -17x -34x = 60 - 20
Step 4: -51x = 40
Step 5: x = 40/-51
2.75 * 12 = 33.
If the Sanchez family is using 2 3/4 (or 2.75) tubes of toothpaste and there are 12 months in a year, we use the equation above and get 33 as our answer.
Note that the formula for the circumference of a circle is πd, while the formula for the area of a circle is πr².
π≈3.14
A. C=πd
Simply plug in the numbers into the formula.
Diameter=Radius*2
17*2=34
C=34(π)
B. (π)(5²)
Plug in the numbers into the formula. Remember that half of the diameter is the radius.
C. (π)(4.5)
There are two possible formulas that could be used to calculate the circumference of a circle: πd and 2πr.
The expression above is simply multiplying the circle's radius times pi. Therefore, it is not a method that could be used to find the circumference of a circle.
D. (π)(6.5²)
Remember that the formula for calculating the area of a circle is πr².
Half of the diameter is 6.5 (13.5/2=6.5). 6.5 cm. is the radius. Now just plug the numbers into the formula.
(π)(6.5²)
Therefore, the last answer choice is the correct answer.
Answer:
Step-by-step explanation:
cos 225 = -cos 45 = -1/√2.
sin 225 = -sin45 = -1√2.