Free PDF download of UP Board Solutions for Balaji Class 10 Maths Solutions Chapter 4 Quadratic Equations Ex 4.3, are provided here, contain detailed explanations of all the problems mentioned in the UP Board Solutions. Students should solve questions from these UP Board solution of class 10, which will help them to prepare well for their exams.
Balaji Class 10 Maths Solutions Chapter 4 Quadratic Equations Ex 4.3 द्विघात समीकरण
निम्नलिखित समीकरणों को हल कीजिए –
प्रश्न 1.
(i) x(x + 1)(x + 3)(x + 4) = 180
(ii) (2x + 3)(2x + 5)(x – 1)(x – 2) = 30
(iii) (x – 5)(x – 7)(x + 4) (UPBoardSolutions.com) (x + 6) = 504
(iv) x(2x + 1)(x – 2)(2x – 3) = 63
(v) (x2 – 3x – 10)(x2 – 5x – 6) = 144
(vi) (x + 2)(3x + 4)(3x + 7)(x + 3) = 2400
हलः
(i) दिया गया समीकरण
{x(x + 1)(x + 3)(x + 4)} = 180
{x(x + 4)}{(x + 1)(x + 3)} = 180
(x2 + 4x)(x2 + x + 3x + 3) = 180
(x2 + 4x)(x2 + 4x + 3) = 180
माना x2 + 4x = y
∴ दिया हुआ समीकरण, y(y + 3) = 180
y2 + 3y – 180 = 0
अब y = 12 लेने पर, x2 + 4x = 12
x2 + 4x – 12 = 0
x2 + 6x (UPBoardSolutions.com) – 2x – 12 = 0
x(x + 6) – 2(x + 6) = 0
(x + 6)(x – 2) = 0
x = 2, – 6
y = 15 लेने पर, x2 + 4x = – 15
x2 + 4x + 15 = 0
(ii) दिया गया समीकरण
(2x + 3) (2x + 5)(x – 1)(x – 2) = 30
{(2x + 3)(x – 1)}{(2x + 5)(x – 2)} = 30
(2x2 – 2x + 3x – 3)(2x2 – 4x + 5x – 10) = 30
(2x2 + x – 3)(2x2 + x – 10) = 30
माना 2x2 + x = y
∴ दिया गया समीकरण
(y – 3)(y – 10) = 30
y2 – 10y – 3y + 30 = 30
y2 – 13y = 0
y(y – 13) = 0
y= 0 व y = 13
जब y = 0, 2x2 (UPBoardSolutions.com) + x = 0
x(2x + 1) = 0
⇒ x = 0, x =
y = 13 लेने पर, 2x2 + x = 13
2x2 + x – 13 = 0
(iii) दिया गया समीकरण
{(x – 5)(x + 4)}{(x – 7)(x + 6)} = 504
(x2 – 5x + 4x – 20)(x2 – 7x + 6x – 42) = 504
(x2 – x – 20)(x2 – x – 42) = 504
माना x2 – x = y
∴ दिया गया समीकरण
(y – 20)(y – 42) = 504
y2 – 20y – 42y + 840 – 504 = 0
y2 – 62y + 336 = 0
y2 – 6y – 56y + 336 (UPBoardSolutions.com) = 0
y(y – 6) – 56(y – 6) = 0
(y – 6)(y – 56) = 0
जब y – 6 = 0 तब y = 6
जब y – 56 = 0
तब y = 56
y = 6 लेने पर, x2 – x = 6
x2 – x – 6 = 0
x2 + 2x – 3x – 6 = 0
x(x + 2) – 3(x + 2) = 0
(x + 2)(x – 3) = 0
x = – 2, 3
y = 56 लेने पर, x2 – x = 56
x2 – x – 56 = 0
x2 – 8x + 7x – 56 = 0
x(x – 8) + 7(x – 8) = 0
(x + 7)(x – 8) = 0
जब x + 7 = 0 तब x = – 7
जब x – 8 = 0 तब x = 8
(iv) दिया गया समीकरण
x(2x + 1)(x – 2)(2x – 3) = 63
{x(2x – 3)} {(2x + 1)(x – 2)} = 63
(2x2 – 3x)(2x2 – 4x + x – 2) = 63
(2x2 – 3x)(2x2 – 3x – 2) = 63
माना 2x2 – 3x (UPBoardSolutions.com) = y
y(y – 2) = 63
y2 – 2y – 63 = 0
y2 – 9y + 7y – 63 = 0
y(y – 9) + 7(y – 9) = 0
(y + 7)(y – 9) = 0
जब y + 7 = 0 तब y = – 7
जब y – 9 = 0 तब y = 9
y = – 7 लेने पर, 2x2 – 3x = – 7
2x2 – 3x + 7 = 0
y = 9 लेने पर, 2x2 – 3x = 9
2x2 – 3x – 9 = 0
2x2 + 3x – 6x – 9 = 0
x(2x + 3) – 3(2x + 3) = 0
(x – 3)(2x + 3) = 0
जब x – 3 = 0 तब (UPBoardSolutions.com) x = 3
जब 2x + 3 = 0 तब x =
(v) दिया गया समीकरण
(x2 – 3x – 10)(x2 – 5x – 6) = 144
(x2 – 5x + 2x – 10)(x2 – 6x + x – 6) = 144
[x(x – 5) + 2(x – 5)][x(x – 6) + 1(x – 6)] = 144
(x – 5)(x + 2)(x + 1)(x – 6) = 144
{(x – 5)(x + 1)}{(x + 2)(x – 6)} = 144
(x2 – 4x – 5) (x2 – 4x – 12) = 144
माना x2 – 4x = y
∴ दिया गया समीकरण,
(y – 5)(y – 12) = 144
y2 – 5y – 12y + 60 – 144 = 0
y2 – 17y – 84 = 0
y2 + 4y – 21y – 84 = 0
y(y + 4) – 21 (y + 4) = 0
(y + 4)(y – 21) = 0
जब y + 4 = 0, (UPBoardSolutions.com) तब y = -4
जब y – 21 = 0, तब y = 21
y = – 4 लेने पर, x2 – 4x + 4 = 0
x2 – 2x – 2x + 4 = 0
x(x – 2) – 2(x – 2) = 0
(x – 2)(x – 2) = 0
x = 2, 2
y = 21 लेने पर, x2 – 4x = 21
x2 – 4x – 21 = 0
x2 – 7x + 3x – 21 = 0
x(x – 7) + 3(x – 7) = 0
x = – 3, 7
(vi) दिया गया समीकरण,
{(x + 2)(3x + 7)} {(3x + 4)(x + 3)} = 2400
(3x2 + 7x + 6x + 14)(3x2 + 9x + 4x + 12) = 2400
(3x2 + 13x + 14) (UPBoardSolutions.com) (3x2 + 13x + 12) = 2400
माना 3x2 + 13x = y
∴ दिया गया समीकरण (y + 14)(y + 12) = 2400
y2 + 14y + 12y + 168 = 2400
y2 + 26y + 168 – 2400 = 0
y2 + 26y – 2232 = 0
y2 – 36y + 62y – 2232 = 0
y(y – 36) + 62(y – 36) = 0
(y – 36)(y + 62) = 0
जब y – 36 = 0 तब y = 36
जब y + 62 = 0 तब y = – 62
y = 36 लेने पर, 3x2 + 13x = 36
3x2 + 13x – 36 = 0
प्रश्न 2.
हल:
(i) दिया गया समीकरण
= 2
= 2 +
3x + 1 = 4 + (x – 1) + 4 (दोनों पक्षों का वर्ग करने पर)
3x – x + 1 – 4 + 1 = 4
2x – 2 = 4 (UPBoardSolutions.com)
2(x – 1) = 2.2
(x – 1) = 2
x2 – 2x + 1 = 4(x – 1) (दोनों पक्षों का पुनः वर्ग करने पर)
x2 – 2x – 4x + 1 + 4 = 0
x2 – 6x + 5 = 0
x2 –x – 5x + 5 = 0
x(x – 1) – 5(x – 1)
(x – 1)(x – 5) = 0
जब (x – 1) = 0 तब x = 1
तथा जब (x – 5) = 0 तब x = 5
(ii) दिया गया समीकरण.
+ = 7
= 7 –
2x + 8 = 49 + (x + 5) (UPBoardSolutions.com) – 14 (दोनों पक्षों का वर्ग करने पर)
2x + 8 – x – 49 – 5 = – 14
x – 46 = – 14
(x – 46)2 = ( – 14)2 (दोनों पक्षों का पुनः वर्ग करने पर)
x2 – 92x + (46)2 = 196(x + 5)
x2 – 92x – 196x + 2116 – 980 = 0
x2 – 288x + 1136 = 0
x2 – 4x – 284x + 1136 = 0
x(x – 4) – 284(x – 4) = 0
यदि x – 4 = 0 तब x = 4
तथा यदि x – 284 = 0 तब x = 284
परन्तु x = 284 समीकरण को सन्तुष्ट नहीं करता।
अतः x = 4
(iii) दिया गया समीकरण,
+ = 2
x + 4 + x + 20 + 2/ = 4(x + 11) (दोनों पक्षों का वर्ग करने पर)
2x + 24 + 21 = 4x + 44
2x + 24 – 4x – 44 =
– 2x – 20 = – 2
– 2(x + 10) = -2
(x + 10) =
x2 + 20x + 100 = x2 + 24x + 80 (दोनों पक्षों का पुन: वर्ग करने पर)
x2 + 20x + 100 – x2 – 24x – 80 = 0
– 4x + 20 = 0
– 4x = – 20
x = 5
(iv) दिया गया समीकरण,
– =
x + 1 + x – 1 – 2 = 4x – 1 (दोनों पक्षों का वर्ग करने पर)
2x – 4x + 1 = 20 (UPBoardSolutions.com)
– 2x + 1 = 2
4x2 + 1 – 4x = 4(x2 – 1) (दोनों पक्षों का पुनः वर्ग करने पर)
4x2 – 4x + 1 – 4x2 + 4 = 0
– 4x + 5 = 0
– 4x = – 5
x =