মধ্য সহগ পদ্ধতি (Middle Term Factorisation)

👇 ax2 + (a + b)x + b আকারের রাশিকে উৎপাদকে বিশ্লেষণ:

🔸 01. ax2 + (a + b)x + b+

ax2 + (a + b)x + b

= ax2 + ax + bx + b

= ax(x + 1) + b(x + 1)

= (x + 1)(ax + b)

🔸 02. 3x2 + 14x + 8+

3x2 + 14x + 8

= 3x2 + (12 + 2)x + 8

= 3x2 + 12x + 2x + 8

= 3x(x + 4) + 2(x + 4)

= (x + 4)(3x + 2)

🔸 03. 6x2 - x - 15+

6x2 - x - 15

= 6x2 - (10 - 9)x - 15

= 6x2 - 10x + 9x - 15

= 2x(3x - 5) + 3(3x - 5)

= (3x - 5)(2x + 3)

🔸 04. 9r2 + r - 8+

9r2 + r - 8

= 9r2 + (9 - 8)r - 8

= 9r2 + 9r - 8r - 8

= 9r(r + 1) - 8(r + 1)

= (r + 1)(9r- 8)

🔸 05. 6m2 - 11mn - 10n2+

6m2 - 11mn - 10n2

= 6m2 - (15 - 4)mn - 10n2

= 6m2 - 15mn + 4mn - 10n2

= 3m(2m - 5n) + 2n(2m - 5n)

= (2m - 5n)(3m + 2n)

🔸 06. 7p2 + 48pq - 7q2+

7p2 + 48pq - 7q2

= 7p2 + (49 - 1)pq - 7q2

= 7p2 + 49pq - pq - 7q2

= 7p(p + 7q) - q(p + 7q)

= (p + 7q)(7p - q)

🔸 07. 12 + a - 6a2+

12 + a - 6a2

= 12 + (12 - 6)a - 6a2

= 12 + 12a - 6a - 6a2

= 12(1 + a) - 6a(1 + a)

= (1 + a)(12 - 6a)

= (1 + a)6(2 - a)

= 6(1 + a)(2 - a)

🔸 08. 6 + 5a - 6a2+

6 + 5a - 6a2

= 6 + (9 - 4)a - 6a2

= 6 + 9a - 4a - 6a2

= 3(2 + 3a) - 2a(2 + 3a)

= (2 + 3a)(3 - 2a)

🔸 09. 99a2 - 202ab + 99b2+

99a2 - 202ab + 99b2

= 99a2 - (121 + 81)ab + 99b2

= 99a2 - 121ab - 81ab + 99b2

= 11a(9a - 11b) - 9b(9a - 11b)

= (9a - 11b)(11a - 9b)

🔸 10. ax2 + (a2 + 1)x + a+

ax2 + (a2 + 1)x + a

= ax2 + a2x + x + a

= ax(x + a) + (x + a)

= (x + a)(ax + 1)

🔸 11. +

=

=

=

=

👇 x2 + (a + b)x + ab আকারের রাশিকে উৎপাদকে বিশ্লেষণ:

🔸 01. x2 + (a + b)x + ab+

x2 + (a + b)x + ab

= x2 + ax + bx + ab

= x(x + a) + b(x + a)

= (x + a)(x + b)

🔸 02. x2 + 7x + 12+

x2 + 7x + 12

= x2 + (4 + 3)x + 4 × 3

= x2 + 4x + 3x + 4 × 3

= x(x + 4) + 3(x + 4)

= (x + 4)(x + 3)

🔸 03. x2 + 7x - 18+

x2 + 7x - 18

= x2 + (9 - 2)x + 9 × (-2)

= x2 + 9x - 2x - 9 × 2

= x(x + 9) - 2(x + 9)

= (x + 9)(x - 2)

🔸 04. x2 + 13x - 48+

x2 + 13x - 48

= x2 + (16 - 3)x - 16 × 3

= x2 + 16x - 3x - 16 × 3

= x(x + 16) - 3(x + 16)

= (x + 16)(x - 3)

🔸 05. (a + b)2 - 5(a + b) - 6+

(a + b)2 - 5(a + b) - 6

ধরি, (a + b) = m

m2 - 5m - 6

= m2 - (6 - 1)m - 6

= m2 - 6m + m - 6

= m(m - 6) + (m - 6)

= (m - 6)(m + 1)

= (a + b - 6)(a + b + 1)

🔸 06. (p2 - 3q2)2 - 16(p2 - 3q2) + 63+

(p2 - 3q2)2 - 16(p2 - 3q2) + 63

ধরি, (p2 - 3q2) = m

m2 - 16m + 63

= m2 - (7 + 9)m + 63

= m2 - 7m - 9m + 63

= m(m - 7) - 9(m - 7)

= (m - 7)(m - 9)

= (p2 - 3q2 - 7)(p2 - 3q2 - 9)

🔸 07. a2 + ab - 12b2+

a2 + ab - 12b2

= a2 + (4 - 3)ab - 12b2

= a2 + 4ab - 3ab - 12b2

= a(a + 4b) - 3b(a + 4b)

= (a + 4b)(a - 3b)

🔸 08. (a + b)2 - 5a - 5b + 6+

(a + b)2 - 5a - 5b + 6

= (a + b)2 - 5(a + b) + 6

ধরি, (a + b) = m

m2 - 5m + 6

= m2 - (3 + 2)m + 6

= m2 - 3m - 2m + 6

= m(m - 3) - 2(m - 3)

= (m - 3)(m - 2)

= (a + b - 3)(a + b - 2)

🔸 09. x4 - 7x2 + 12+

x4 - 7x2 + 12

= (x2)2 - 7x2 + 12

ধরি, x2 = m

m2 - 7m + 12

= m2 - (4 + 3)m + 12

= m2 - 4m - 3m + 12

= m(m - 4) - 3(m - 4)

= (m - 4)(m - 3)

= (x2 - 4)(x2 - 3)

= (x2 - 22)(x2 - 3)

= (x - 2)(x + 2)(x2 - 3)

🔸 10. x6y6 - 9x3y3 + 8+

x6y6 - 9x3y3 + 8

= (x3y3)2 - 9x3y3 + 8

ধরি, x3y3 = m

= m2 - 9m + 8

= m2 - (8 + 1)m + 8

= m2 - 8m - m + 8

= m(m - 8) - (m - 8)

= (m - 8)(m - 1)

= (x3y3 - 8)(x3y3 - 1)

= {(xy)3 - 23}{(xy)3 - 13}

= {(xy) - 2}{(xy)2 + (xy).2 + 22}{(xy) - 1}{(xy)2 + (xy) + 12}

= (xy - 2)(x2y2 + 2xy + 4)(xy - 1)(x2y2 + xy + 1)

🔸 11. x2 − 2ax + (a + b)(a − b)+

x2 − 2ax + (a + b)(a − b)

= x2 − {(a + b) + (a − b)} x + (a + b)(a − b)

= x2 − (a+b)x − (a − b)x + (a + b)(a − b)

= x{x − (a + b)} − (a − b){x − (a + b)}

= {x − (a + b)}{x − (a − b)}

= (x − a − b)(x − a + b)

🔸 12. x2 − bx - (a + 3b)(a + 2b)+

x2 − bx - (a + 3b)(a + 2b)

= x2 − {(a + 3b) - (a + 2b)} x - (a + 3b)(a + 2b)

= x2 − (a + 3b)x + (a + 2b) x - (a + 3b)(a + 2b)

= x{x − (a + 3b)} + (a + 2b){x − (a + 3b)}

= {x − (a + 3b)}{x + (a + 2b)}

= (x − a − 3b)(x + a + 2b)

🔸 13. p2 + p - (a + 1)(a + 2)+

p2 + p - (a + 1)(a + 2)

= p2 + {(a + 2) - (a + 1)} p - (a + 1)(a + 2)

= p2 + (a + 2)p - (a + 1) p - (a + 1)(a + 2)

= p{p + (a + 2)} - (a + 1){p + (a + 2)}

= {p + (a + 2)}{p - (a + 1)}

= (p + a + 2)(p - a - 1)

🔸 14. (x2 + 1)2 - (x2 - 1) - 4x2+

(x2 + 1)2 - (x2 - 1) - 4x2

= (x2 - 1)2 + 4.x2.1 - (x2 - 1) - 4x2

= (x2 - 1)2 + 4x2 - (x2 - 1) - 4x2

= (x2 - 1)2 - (x2 - 1)

= (x2 - 1){(x2 - 1) - 1}

= (x2 - 12)(x2 - 2)

= (x + 1)(x - 1)(x2 - 2)

🔸 15. x2 + 2(a2 + b2)x + (a2 - b2)2+

x2 + 2(a2 + b2)x + (a2 - b2)2

= x2 + 2(a2 + b2)x + {(a + b)(a - b)}2

= x2 + {(a + b)2 + (a - b)2}x + (a + b)2(a - b)2

= x2 + (a + b)2x + (a - b)2x + (a + b)2(a - b)2

= {x + (a + b)2}x + (a - b)2{x + (a + b)2}

= {x + (a + b)2}{x + (a - b)2}

= (x + a2 + 2ab + b2)(x + a2 - 2ab + b2)