Answer:
Step-by-step explanation:
- 10x² - 7ax + (a + 2) (a - 5) =
- 10x² - 7ax + a² - 3a - 10
Factorize by finding the roots
<u>Find the discriminant:</u>
- D = b² - 4ac
- D = (-7a)² - 4*10*(a² - 3a - 10) =
- 49a² - 40a² + 120a + 400 =
- 9a² + 120a + 400 =
- (3a + 20)²
<u>Find the roots:</u>
- x = (- b ± √D)/2a = (7a ± (3a + 20)) / 20
- x₁ = (7a + 3a + 20) / 20 = (10a + 20) / 20 = (a + 2) / 2
- x₂ = (7a - 3a - 20) / 20 = (4a - 20) / 20 = (a - 5) / 5
<u>Factorize the expression:</u>
- 10x² - 7ax + a² - 3a - 10 =
- 10 (x - x₁)(x - x₂) =
- 10[x - (a + 2)/2][[x - (a - 5)/5] =
- (2x - a - 2)(5x - a + 5)
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<u>You would also try a shorter but more difficult way:</u>
- 10x² - 7ax + (a + 2) (a - 5) =
- 2x*5x - 2ax + 10x - 5ax - 10x + (a + 2) (a - 5) =
- 2x*5x - 2x(a - 5) - 5x(a + 2) + (a + 2) (a - 5) =
- 2x(5x - (a - 5)) - (a + 2)(5x - (a - 5)) =
- (5x - a + 5)(2x - a - 2)
Answer:
300
Step-by-step explanation:
(75*4)/1
Answers are:
16.
-1 - (-4) = 3
17.
-1-1/3 - (-4) = 2-2/3
18.
2 - (-1) = 3
19.
3-1/2 - (-1) = 4-1/2
20.
3-1/2 - 2 .= 1-1/2
21.
3-1/2 - (-1-1/3) = 4-5/6
Step by step: I took one point and subtracted the second point to get the length of each segment. You could also look at the ruler and count from one point to the other.
Remember when you subtract a negative, the two negatives become a positive
The answer is B. Hope it helped
Answer:
654 feet
Step-by-step explanation:
a climber starts from 574 ft above sea level till reaches 80 below sea level.
how many feet did the climber descend?
= 574 to 0, then 0 to 80
= 574 + 80
= 654 feet
