3x+2(5x-3)=7
3x+10x-6=7
13x-6=7
13x=13
x=1
The answer is 69.6 degrees because all of the angles of a triangle always add up to 180 degrees so adding 42 and 68.4 gets 110.4, and then subtracting that from 180 gets 69.9.
The correct option is "d".
Given that L = 0.8T²
length of pendulum = 30ft
L= 0.8T²
30 = 0.8T²
T² = 30 / 0.8
T² = 37.5
T = √37.5 = 6.1 seconds
<span>So, 6.1 is the closest to the period in seconds for a pendulum that is 30 ft long.</span>