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)
4/16 add all then put your total black over the number you added up
5.19cm
Step-by-step explanation:
draw perpendicular from the center of the circle to produce a right angle triangle which will have 3cm and an angle of 30 degrees. use tan to find the adjacent line which is the length of the tangent.
7 1/2 - 1 1/4 = 7 2/4 - 1 1/4 = 6 1/4
