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)
====================================================
<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:
There are total 55 counters out of which 11 are green and 44 are other color.
Step-by-step explanation:
This is a ratio and proportion question. There are c amount of counters in the box .
The chosen have the same ratio as in the box
Green : total
4: 20
11: x
Using cross product rule
x * 4= 20 *11
x= 20*11/4
x= 55
So there are total 55 counters out of which 11 are green and 44 are other color.
Benedict take 20 counters out of which 4 are green.
i thibfergghgearsssgggga. dddyssxxv d xxx can find different
Answer:
-2.5
Step-by-step explanation:
5+3(5)/-2
5+15/-2
5+-7.5=-2.5
