2(x + 2) + 2 = 2(x + 3) + 1
2x + 4 + 2 = 2x + 6 + 1
2x + 6 = 2x + 7 - NO SOLUTION
(subtract 2x from both sides, then 6 = 7 FALSE)
2x + 3(x + 5) = 5(x – 3)
2x + 3x + 15 = 5x - 15
5x + 15 = 5x - 15 - NO SOLUTION
4(x + 3) = x + 12
4x + 12 = x + 12 - ONE SOLUTION
4 – (2x + 5) = (–4x – 2)
4 - 2x - 5 = -4x - 2
-2x - 1 = -4x - 2 - ONE SOLUTION
5(x + 4) – x = 4(x + 5) – 1
5x + 20 - x = 4x + 20 - 1
4x + 20 = 4x + 19 - NO SOLUTION
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.
Answer:
12
Step-by-step explanation:
Solving the equation would be the easiest way to find out which number fits.
6x - 18 = 54
6x = 72
x = 12
7 is 1/10 of.. 70, because 10 times 7 is 70 :)
Look in the images it is solved.
