Answer:
B
Step-by-step explanation:
Given
4x² - 72x = 0 ← factor out 4 from each term
4(x² - 18x) = 0
To complete the square
add/subtract (half the coefficient of the x- term)² to x² - 18x
4(x² + 2(- 9)x + 81 - 81) = 0
4(x - 9)² - 4(81) = 0
4(x - 9)² - 324 = 0 ( add 324 to both sides )
4(x - 9)² = 324 ( divide both sides by 4 )
(x - 9)² = 81 ( take the square root of both sides )
x - 9 = ± = ± 9 ( add 9 to both sides )
x = 9 ± 9
Then
x = 9 - 9 = 0
x = 9 + 9 = 18
Answer:
Step-by-step explanation:
In order to solve this, we are trying to find the value of . Basically,
is a placeholder for a number that is unknown. Some number minus 3 is equal to 21.
Our goal is to find . To do this we want to isolate
on one side of the equation
Let's add 3 to both sides.
Hope this helped!
You have to watch 30 movies to earn a free movie pass.
Step-by-step explanation:
Given,
Points earned for each movie = 2 points
Current points = 40 points
Free movie pass = 100 points
Let,
x be the number of movies you have to watch.
2*number of movies + current points = 100
Subtracting 40 from both sides
Dividing both sides by 2
You have to watch 30 movies to earn a free movie pass.
Keywords: linear equation, division
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