Class IX - Factorisation
Math
Exercise 8.2
নবম শ্রেণী
অংক
কষে দেখি - 8.2
উৎপাদকে বিশ্লেষণ
1. $ \frac {x⁴}{16} - \frac {y⁴}{81}$
2. $m^2+\frac1{m^2}+2-2m-\frac2m$
3. 9p² -24pq + 16q² + 3ap - 4aq
4. 4x⁴ + 81
5. x⁴ - 7x² + 1
6. p⁴ - 11p²q² + q⁴
7. a² + b² - c² - 2ab
8. 3a(3a + 2c) - 4b (b + c)
9. a² - 6ab + 12be - 4c²
10. 3a² + 4ab + b² - 2ac - c²
11. x² - y² - 6ax + 2ay + 8a²
12. a² - 9b² + 4c² - 25d² - 4ac + 30bd
13. 3a² - b² - c² + 2ab - 2bc + 2ca
14. x² - 2x - 22499
15. (x² - y²) (a² - b²) + 4abxy
1. $ \frac {x⁴}{16} - \frac {y⁴}{81}$
Ans.
$\frac {x⁴}{16} - \frac {y⁴}{81}$
= $(\frac {x²}{4} )^2- (\frac {y²}{9})^2$
= $\left(\frac{x²}4+\frac{y²}9\right)\left(\frac{x²}4-\frac{y²}9\right)$
= $\left(\frac{x²}4+\frac{y²}9\right)\left\{\left(\frac x2\right)^2-\left(\frac y3\right)^2\right\} $
= $\left(\frac{x²}4+\frac{y²}9\right)\left(\frac x2+\frac y3\right)\left(\frac x2-\frac y3\right) $
উত্তর: নির্ণয় উৎপাদক $\left(\frac{x²}4+\frac{y²}9\right)\left(\frac x2+\frac y3\right)\left(\frac x2-\frac y3\right) $
2. $m^2+\frac1{m^2}+2-2m-\frac2m$
Ans.
$m^2+\frac1{m^2}+2-2m-\frac2m$
= $m^2+2+\frac1{m^2}-2m-\frac2m$
= $m^2+2.m.\frac1m+\frac1{m^2}-2m-\frac2m$
=$\left(m+\frac1m\right)^2-2\left(m+\frac1m\right)$
=$\left(m+\frac1m\right)\left(m+\frac1m-2\right)$
উত্তর: নির্ণয় উৎপাদক $\left(m+\frac1m\right)\left(m+\frac1m-2\right)$
3. 9p² -24pq + 16q² + 3ap - 4aq
Ans.
9p² -24pq + 16q² + 3ap - 4aq
= (3p)² - 2.3p.4q + (4q)² + 3ap - 4aq
= (3p - 4q)² + a(3p -4q)
= (3p - 4q){(3p - 4q) + a}
= (3p - 4q)(3p - 4q + a)
উত্তর: নির্ণয় উৎপাদক (3p - 4q)(3p - 4q + a)
4. 4x⁴ + 81
Ans.
4x⁴ + 81
= (2x²)² + (9)²
= (2x² + 9)² - 2.2x².9
= (2x² + 9)² - 36x²
= (2x² + 9)² - (6x)²
= {(2x² + 9) + 6x}{(2x² + 9) - 6x}
= (2x² + 9 + 6x)(2x² + 9 - 6x)
= (2x² + 6x + 9)(2x² - 6x + 9)
উত্তর: নির্ণয় উৎপাদক (2x² + 6x + 9)(2x² - 6x + 9)
5. x⁴ - 7x² + 1
Ans.
x⁴ - 7x² + 1
= x⁴ + 2x² + 1 - 7x² - 2x²
= (x²)² + 2.x².1 + (1)² - 9x²
= (x² + 1)² - (3x)²
= {(x² + 1) + (3x)} {(x² + 1) - (3x)}
= (x² + 1 + 3x)(x² + 1 - 3x)
= (x² + 3x + 1)(x² - 3x + 1)
উত্তর: নির্ণয় উৎপাদক (x² + 3x + 1)(x² - 3x + 1)
6. p⁴ - 11p²q² + q⁴
Ans.
p⁴ - 11p²q² + q⁴
= (p²)² - 2p²q² + (q²)² - 9p²q²
= (p² - q²)² - (3pq)²
= {(p² - q²) + (3pq)} {(p² - q²) - (3pq)}
= (p² - q² + 3pq)= (p² - q² - 3pq)
= (p² + 3pq - q²)= (p² - 3pq - q²)
উত্তর: নির্ণয় উৎপাদক (p² + 3pq - q²)= (p² - 3pq - q²)
7. a² + b² - c² - 2ab
Ans.
a² + b² - c² - 2ab
= a² - 2ab + b² - c²
= (a - b)² - c²
= {(a - b) + c}{(a - b) - c}
= (a - b + c) (a - b - c)
উত্তর: নির্ণয় উৎপাদক (a - b + c) (a - b - c)
8. 3a(3a + 2c) - 4b (b + c)
Ans.
3a(3a + 2c) - 4b (b + c)
= 9a² + 6ac - 4b² - 4bc
= 9a² - 4b² + 6ac - 4bc
= (3a)² - (2b)² + 6ac - 4bc
= (3a + 2b)(3a - 2b) + 2c(3a - 2b)
= (3a - 2b){(3a + 2b) + 2c}
= (3a - 2b) (3a + 2b + 2c)
উত্তর: নির্ণয় উৎপাদক (3a - 2b) (3a + 2b + 2c)
9. a² - 6ab + 12be - 4c²
Ans.
a² - 6ab + 12bc - 4c²
= a² - 4c² - 6ab + 12bc
= (a)² - (2c)² - 6ab + 12bc
= (a + 2c)(a - 2c) - 6b(a - 2c)
= (a - 2c) {(a + 2c) - 6b}
= (a - 2c) (a + 2c - 6b)
= (a - 2c) (a - 6b + 2c)
উত্তর: নির্ণয় উৎপাদক (a - 2c) (a - 6b + 2c)
10. 3a² + 4ab + b² - 2ac - c²
Ans.
3a² + 4ab + b² - 2ac - c²
= 4a² + 4ab + b² - a² - 2ac - c²
=(2a)² + 2.2a.b + b² - a² - 2ac - c²
= {(2a)² + 2.2a.b + b²} - (a² + 2ac + c²)
= (2a + b)² - (a + c)²
= {(2a + b) + (a + c)}{(2a + b) - (a + c)}
= (2a + b + a + c)(2a + b - a - c)
= (3a + b + c) (a + b - c)
উত্তর: নির্ণয় উৎপাদক (3a + b + c) (a + b - c)
11. x² - y² - 6ax + 2ay + 8a²
Ans.
x² - y² - 6ax + 2ay + 8a²
= x² - 6ax + 9a² - y² + 2ay - a²
= x² - 2.x.3a + (3a)² - (y² - 2.y.a + a²)
= (x - 3a)² - (y - a)²
= {(x - 3a) + (y - a)} {(x - 3a) - (y - a)}
= (x - 3a + y - a) (x - 3a - y + a)
= (x + y - 4a)(x - y - 2a)
উত্তর: নির্ণয় উৎপাদক (x + y - 4a)(x - y - 2a)
12. a² - 9b² + 4c² - 25d² - 4ac + 30bd
Ans.
a² - 9b² + 4c² - 25d² - 4ac + 30bd
= a² - 4ac + 4c² - 9b² + 30bd - 25d²
= (a² - 4ac + 4c²) - (9b² - 30bd + 25d²)
= {a² - 2.a.2c + (2c)²} - {(3b)² + 2.3b.5d - (5d)²}
= (a - 2c)² - (3b - 5d)²
= {(a - 2c) + (3b - 5d)} {(a - 2c) - (3b - 5d)}
= (a - 2c + 3b - 5d) (a - 2c - 3b + 5d)
=(a + 3b - 2c - 5d) (a - 3b - 2c + 5d)
উত্তর: নির্ণয় উৎপাদক (a + 3b - 2c - 5d) (a - 3b - 2c + 5d)
13. 3a² - b² - c² + 2ab - 2bc + 2ca
Ans.
3a² - b² - c² + 2ab - 2bc + 2ca
= 4a² - a² - b² - c² + 2ab - 2bc + 2ca
= 4a² - (a² + b² + c² - 2ab + 2bc - 2ca)
= 4a² - {a² + (-b)² + (-c)² + 2.a.(-b) + 2(-b).(-c) + 2(-c).a}
= 4a² - {a + (-b) + (-c)}²
= 4a² - (a - b - c)²
= (2a)² - (a - b - c)²
= {2a + (a - b - c)}{2a - (a - b - c)}
= (2a + a - b - c) (2a - a + b + c)
= (3a - b - c) (a + b + c)
উত্তর: নির্ণয় উৎপাদক (3a - b - c) (a + b + c)
14. x² - 2x - 22499
Ans.
x² - 2x - 22499
= x² - 2x +1 -1 - 22499
= (x² - 2x +1) - 22500
= (x - 1)² - (150)²
= {(x - 1) + 150} {(x - 1) - 150}
= (x - 1 + 150) (x - 1 - 150)
= (x +149) (x -151)
উত্তর: নির্ণয় উৎপাদক (x +149) (x -151)
15. (x² - y²) (a² - b²) + 4abxy
Ans.
(x² - y²) (a² - b²) + 4abxy
= a²x² - a²y² - b²x² + b²y² + 4abxy
= a²x² + 2abxy + b²y² - b²x² + 2abxy - a²y²
= (ax)² + 2.ax.by + (by)² - (bx)² + 2.bx.ay - (ay)²
= {(ax)² + 2.ax.by + (by)²} - {(bx)² - 2.bx.ay + (ay)²}
= (ax + by)² - (bx - ay)²
= {(ax + by) + (bx - ay)} {(ax + by) - (bx - ay)}
= (ax + bx - ay + by) (ax - bx + ay + by)
উত্তর: নির্ণয় উৎপাদক (ax + bx - ay + by) (ax - bx + ay + by)
আরও দেখুন
0 মন্তব্যসমূহ
Your comment will be visible after approval