Find mZB.
Round to the nearest degree.
11
B В
7.
15

m∠B = 111º

Step-by-step explanation:

use law of cosines

c² = a² + b² - 2ab*cosC

15² = 7² + 11² - 2(7)(11)cosB

225 = 49 + 121 - 154cosB

225 = 170 - 154cosB

Subtract 170 form both sides

55 = -154cosB

Divide both sides by -154

-0.3571428571 = cosB

m∠B = arccos -0.3571428571

use calculator

m∠B = 110.924832425009406

Rounded

m∠B = 111º

answer: solve 5\cdot 2^x=2405⋅2  

x

=2405, dot, 2, start superscript, x, end superscript, equals, 240.

solution

to solve for xxx, we must first isolate the exponential part. to do this, divide both sides by 555 as shown below. we do not multiply the 555 and the 222 as this goes against the order of operations!

\begin{aligned} 5\cdot 2^x& =240 2^x& =48 \\ \end{aligned}  

5⋅2  

x

2  

x

​    

=240

=48

​

step-by-step explanation: