Haryana State Board HBSE 8th Class Maths Solutions Chapter 14 गुणनखंडन Ex 14.1 Textbook Exercise Questions and Answers.
Haryana Board 8th Class Maths Solutions Chapter 14 गुणनखंडन Ex 14.1
प्रश्न 1.
दिये गये पदों में सार्व गुणनखण्ड ज्ञात कीजिए-
(i) 12x, 36
(ii) 2y, 22xy
(iii) 14pq, 28 p2q2
(iv) 2x, 3x2, 4
(v) 6abc, 24 ab2, 12a2b
(vi) 16x3, -4x2, 32x
(vii) 10pq, 20qr, 30rp
(viii) 3x2y3, 10x3y2, 6x2y2z
हल:
(i) 12x = 2 × 2 × 3 × x
36 = 2 × 2 × 3 × 3
सार्व गुणनखण्ड = 2 × 2 × 3 = 12
∴ सार्व गुणनखण्ड = 12
(ii) 2y, 22xy
2y = 2 × y
22xy = 2 × 11 × x × y
सार्व गुणनखण्ड 2 व y है। तो
सार्व गुणनखण्ड = 2 × y = 2y
(iii) 14pq, 28 p2q2
14pq = 2 × 7 × p × q
28 p2q2 = 2 × 2 × 7 × p × p × q × q
∴ सार्व गुणनखण्ड = 2 × 7 × p × q
= 14 pq
∴ सार्व गुणनखण्ड = 14 pq
(iv) 2x, 3x2, 4
2x, 3x2, 4
2x = 2 × x
3x2 = 3 × x × x
4 = 2 × 2 × 1
∴ सार्व गुणनखण्ड = 1
(v) 6abc, 24 ab2, 12a2b
6abc = 2 × 3 × a × b × c
24 ab2 = 2 × 2 × 2 × 3 × a × b × b
12a2b = 2 × 2 × 3 × a × a × b
सार्व गुणनखण्ड 2, 3, a और b हैं।
∴ सार्व गुणनखण्ड = 2 × 3 × a × b
= 6ab
(vi) 16x3, -4x2, 32x
16x3 = 2 × 2 × 2 × 2 × x × x × x
-4x2 = -1 × 2 × 2 × x × x
32x = 2 × 2 × 2 × 2 × 2 × x
सार्व गुणनखण्ड 2, 2, और x हैं।
∴ सार्व गुणनखण्ड = 2 × 2 × x = 4x
(vii) 10pq, 20qr, 30rp
10pq = 2 × 5 × p × q
20qr = 2 × 2 × 5 × q × r
30rp = 2 × 3 × 5 × r × p
सार्व गुणनखण्ड 2 और 5 हैं।
∴ सार्व गुणनखण्ड = 2 × 5 = 10
(viii) 3x2y3, 10x3y2, 6x2y2z
3x2y3 = 3 × x × x × y × y × y
10 x3 y2 = 2 × 5 × x × x × x y × y
6x2y2z = 2 × 3 × x × x × y × y × z
सार्व गुणनखण्ड x, x, y और y हैं।
= x × x × y × y
सार्व गुणनखण्ड = x2y2
प्रश्न 2.
निम्नलिखित व्यंजकों के गुणनखंड कीजिए
(i) 7x – 42
(ii) 6p – 12q
(iii) 7a2 + 14a
(iv) -16z + 20z3
(v) 20l2m + 30alm
(vi) 5x2y – 15xy2
(vii) 10a2 – 15b2 + 20c2
(viii) -4a2 + 4ab – 4ca
(ix) x2yz + xy2z + xyz2
(x) ax2y + bxy2 + cxyz
Solution:
(i) 7x – 42
= 7x – 7 × 6
= 7(x – 6)
∴ 7x – 42 = 7(x – 6)
(ii) 6p – 12q
= 6p – 6 × 2q
= 6 (p – 2q)
∴ 6p – 12q = 6 (p – 2q)
(iii) 7a2 + 14a
= 7a2 + 7 × 2a
= 7a (a + 2)
∴ 7a2 + 14a = 7a (a + 2)
(iv) -16z + 20z3
= 42 (-4z + 5z2)
= 4z (5z2 – 4z)
∴ -16z + 20z3 = 4z (5z2 – 4z)
(v) 20l2m + 30alm
= (2 × 2 × 5 × l × l × m) + (3 × 2 × 5 × a × l × m)
= 2 × 5 lm (2 × l + 3 × a)
= 10lm (2l + 3a)
∴ 20l2m + 30alm = 10lm (2l + 3a)
(vi) 5x2y – 15xy2
= (5 × x × x × y) – (3 × 5 × x × y)
= 5 xy (x – 3y)
∴ 5x2y – 15xy2 = 5xy (x – 3y)
(vii) 10a2 – 15b2 + 20c2
= (2 × 5 × a × a) – (3 × 5 × b × b × b) + (2 × 2 × 5 × c × c)
= 5 × (2 × a × a – 3 × b × b + 4 × c × c)
= 5 (2a2 – 3b2 + 4c2)
∴ 10a2 – 15b2 + 20c2 = 5 (2a2 – 3b2 + 4c2)
(viii) -4a2 + 4ab – 4ca
= – (4 × a × a) + (4 × a × b) – (4 × c × a)
= 4a(-a + b – c)
∴ -4a2 + 4ab – 4ca = 4a(-a + b – c)
(ix) x2yz + xy2z + xyz2
= (x × x × y × z) + (x × y × y × z) + (x × y × z × z)
= xyz (x + y + z)
∴ x2yz + xy2z + xyz2 = xyz (x + y + z)
(x) ax2y + bxy2 + cxyz
= (a × x × x × y) + (b × x × y × y) + (c × x × y × z)
= xy (ax + by + cz)
∴ ax2y + bxy2 + cxyz = xy (ax + by + cz)
प्रश्न 3.
गुणनखंड कीजिए
(i) x2 + xy + 8x + 8y
(ii) 15xy – 6x + 5y – 2
(iii) ax + bx – ay – by
(iv) 15pq + 15 + 9q + 25p
(v) z – 7 + 7xy – xyz
हल:
(i) x2 + xy + 8x + 8y
= (x2 + xy) + (8x + 8y)
= x (x + y) + 8 (x + y)
= (x + y)(x + 8)
(ii) 15xy – 6x + 5y – 2
= (15xy – 6x) + (5y – 2)
= 3x (5y – 2) + 1 (5y – 2)
= (5y – 2) (3x + 1)
(iii) ax + bx – ay – by
= (ax + bx) – (ay – by)
= x(a + b) – y (a + b)
= (a + b) (x – y)
(iv) 15pq + 15 + 9q + 25p
= (15pq + 15) + (9q + 25p)
= 15pq + 9q + 25p + 15
= 3q + (5p + 3) + 5 (5p + 3)
= (5p + 3) (3q + 5)
(v) z – 7 + 7xy – xyz
= (z – 7) + (7xy – xyz)
= 1 (z – 7) – xy (z – 7)
= (z – 7)(1 – xy)