the answer is 80 take the positive and negative and use the sign change rule
Do you remember when you were learning about
Least Common Multiple (LCM) ? And you were
wondering what on Earth you would ever need it for ?
THIS IS IT !
The amount of time after 8 PM when the lights will flash
together again is the LCM of 20 seconds and 30 seconds.
Do you remember how to find it ?
... When 20 is prime-factored, you have 2 · 2 · 5 .
... When 30 is prime-factored, you have 2 · 3 · 5 .
... So the Least Common Multiple of 20 and 30 is 2 · 2 · 3 · 5 = 60 .
The lighthouses will flash together again in 60 seconds after 8 PM.
That'll be 8:01 PM.
Some information is missing for #6.
#7: use sine, sin35=h/5.1, h=5.1*sin35, use a calculator, h≈2.9
#23: to find the reference angle, keep subtracting the number by 360, until the remaining difference is the smallest positive number.
1406-360-360-360=326. the reference angle is 326.
now look at the remainder, the terminal line of 326 degree is in the 4th quadrant between 270 and 360, the the reference angle is 360-326=34, the angle between the terminal line and the positive x axis. 34 is the answer.
Answer:
there is no solution
Step-by-step explanation:
