So,

9*27 + 2*31 - 28 = n

We use PEMDAS.

Multiply from left to right.
243 + 2*31 - 28 = n
243 + 62 - 28 = n

Add or subtract from left to right.
305 - 28 = n
277 = n

4 0

3 years ago

What is the length of the arc if: 11. r=10 n=20 A15(pi)/ 7 B13(pi)/ 5 C16(pi)/ 2 D11(pi)/ 4 E 10(pi)/ 9 F 9(pi)/ 4 12. r=3 n=6 A

Vilka [71]

Step-by-step explanation:

The formula for arc length [for the angle in degrees] is:

$L = 2\pi r \left(\dfrac{n}{360}\right)$

here,

$n$ = degrees

$r$ = radius

using this we'll solve all the parts:

r = 10, n = 20:

$L = 2\pi r \left(\dfrac{n}{360}\right)$

$L = 2\pi (10) \left(\dfrac{20}{360}\right)$

from here, it is just simplification:

2 and 360 can be resolved: 360 divided by 2 = 180

$L = \pi (10) \left(\dfrac{20}{180}\right)$

10 and 180 can be resolved: 180 divided by 10 = 18

$L = \pi \left(\dfrac{20}{18}\right)$

finally, both 20 and 18 are multiples of 2 and can be resolved:

$L = \pi \left(\dfrac{10}{9}\right)$

$L = \dfrac{10\pi}{9}$ Option (E)

r=3, n=6:

$L = 2\pi r \left(\dfrac{n}{360}\right)$

$L = 2\pi (3) \left(\dfrac{6}{360}\right)$

$L = \dfrac{\pi}{10}$ Option (D)

r=4 n=7

$L = 2\pi r \left(\dfrac{n}{360}\right)$

$L = 2\pi (4) \left(\dfrac{7}{360}\right)$

$L = \dfrac{7\pi}{45}$ Option (C)

r=2 n=x

$L = 2\pi r \left(\dfrac{n}{360}\right)$

$L = 2\pi (2) \left(\dfrac{x}{360}\right)$

$L = \dfrac{x\pi}{90}$ Option (D)

r=y n=x

$L = 2\pi r \left(\dfrac{n}{360}\right)$

$L = 2\pi (y) \left(\dfrac{x}{360}\right)$

$L = \dfrac{xy\pi}{180}$ Option (E)

6 0

3 years ago