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Questions :
1. Find the common factors of the given terms :
(a) 9xy² , 27x²y
Common factors - 9xy .
(b) 12ab³c² , -24 a³b³c², - 15 a²b²c² .
Common factors > 3 a b²c² .
2. Factorise the following
(a) 45 xyz² - 5 xy²z
> 5xyz ( 9z - y )
(b) 4x²y³ - 12 x³y + 18 x⁴y³
> 2x²y ( 2y² - 6 x + 9 x²y²)
3. Factorise the following .
(a) . a³ - 2a²b + 3ab² - 6 b³
> a² ( a - 2b ) + 3b²( a - 2b )
> ( a - 2b )( a² + 3b² )
(b) 6pq + 6 - 9p - 4q
> 6pq - 4q + 6 - 9p
> 2q ( 3p - 2 ) - 3( 3p - 2)
> ( 3p - 2)( 2q - 3)
(c) 25 ( x - y )³ - 15( x - y )² .
> 5( x - y)² [ 5( x - y ) - 3 ]
>5( x - y )²( 5x - 5y - 3)
4. Factorise using Identities -
(a) 36x² - 49b².
> [ 6x ]² - [ 7b ]²
> [ 6x + 7b ][ 6x - 7b ]
(b) 36y² + 36y + 9
> 9 [ 4y² + 4y + 1 ]
> 9 [ 4y² + 2y + 2y + 1 ]
> 9[ 2y( 2y + 1) + ( 2y + 1) ]
> 9( 2y + 1)².
(c) 9x⁴ - 6x²y² + y⁴ .
> [ 3x² ]² - 2[ 3x² ][ y² ] + [ y² ]²
> [ 3x² - y² ]² .
(D) a² - b² - 4ac + 4c²
>[ a² - 4ac + 4c² ] - b²
> [ a - 2c ]² - b²
> [ a + b - 2c ][ a - b - 2c ]
(e) z⁴ - 256
> [ z² ]² - [ 16 ]²
> [ z² + 16 ][ z² - 16]
> [ z² + 16 ][ z + 4 ][ z - 4 ]
(f) . ( x + y )² - ( x - y )² .
> [ x + y + x - y ][ x + y - x + y ]
> [ 2x ][ 2y ]
> 4xy .
(g) . 9/25 a² - 16/64 b².
> 9/25 a² - 1/4 b²
> [ ⅗ a ]² - [ ½ b ]² .
> [ ⅗ a + ½ b ][ ⅗ a - ½ b ] .
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Additional Information -
(a + b)² = a² + 2ab + b²
(a + b)² = (a - b)² + 4ab
(a - b)² = a² - 2ab + b²
(a - b)² = (a + b)² - 4ab
a² + b² = (a + b)² - 2ab
a² + b² = (a - b)² + 2ab
2 (a² + b²) = (a + b)² + (a - b)²
4ab = (a + b)² - (a - b)²
ab = {(a + b)/2}² - {(a-b)/2}²
(a + b + c)² = a² + b² + c² + 2(ab + bc + ca)
(a + b)³ = a³ + 3a²b + 3ab² b³
(a + b)³ = a³ + b³ + 3ab(a + b)
(a - b)³ = a³ - 3a²b + 3ab² - b³
a³ + b³ = (a + b)( a² - ab + b² )
a³ + b³ = (a + b)³ - 3ab( a + b)
a³ - b³ = (a - b)( a² + ab + b²)
a³ - b³ = (a - b)³ + 3ab ( a - b )
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Question (1) :- Find the given factors of the given terms .
- a) 9xy², 27x²y .
- b) 12ab³c² , (-24)a³b³c², (-15)a²b²c² .
Solution (a):-
writing both expressions in expand form we get,
→ 9xy² = 3 * 3 * x * y * y
→ 27x²y = 3 * 3 * 3 * x * x * y
therefore,
→ common factors = 3 * 3 * x * y = 9xy (Ans.)
Solution (b):-
writing given expressions in expand form we get,
→ 12ab³c² = 3 * 2 * 2 * a * b * b * b * c * c
→ (-24)a³b³c² = (-1) * 3 * 2 * 2 * 2 * a * a * a * b * b * b * c * c
→ (-15)a²b²c² = (-1) * 5 * 3 * a * a * b * b * c * c
therefore,
→ common factors = 3 * a * b * b * c * c = 3ab²c² (Ans.)
________________
Question (2) , (3):- Factorise the following :-
- a) 45xyz² - 5xy²z
- b) 4x²y³ - 12x³y + 18x⁴y³
- c) a³ - 2a²b + 3ab² - 6b³
- d) 6pq + 6 - 9p - 4q
- e) 25(x - y)³ - 15(x - y)²
Solution (a) :-
→ 45xyz² - 5xy²z
→ 5 * 9 * x * y * z * z - 5 * x * y * y * z
taking common , we get,
→ 5xyz(9z - y) (Ans.)
Solution (b) :-
→ 4x²y³ - 12x³y + 18x⁴y³
→ 2 * 2 * x * x * y * y * y - 2 * 2 * 3 * x * x * x * y + 2 * 3 * 3 * x * x * x * x * y * y * y
taking common , we get,
→ 2*x*x*y(2*y*y - 2*3*x + 3*3*x*x*y*y)
→ 2x²y(2y² - 6x + 9x²y²) (Ans.)
Solution (c) :-
→ a³ - 2a²b + 3ab² - 6b³
→ a²(a - 2b) + 3b²(a - 2b)
taking (a - 2b) common now,
→ (a - 2b)(a² + 3b²) (Ans.)
Solution (d) :-
→ 6pq + 6 - 9p - 4q
re - arranging the like terms,
→ 6pq - 4q + 6 - 9p
taking common now,
→ 2q(3p - 2) - 3(3p - 2)
taking (3p - 2) as common now,
→ (3p - 2)(2q - 3) (Ans.)
Solution (e) :-
→ 25(x - y)³ - 15(x - y)² .
taking 5 common first,
→ 5[5(x - y)³ - 3(x - y)²]
taking (x - y)² common now,
→ 5(x - y)²[ 5(x - y) - 3]
→ 5(x - y)²(5x - 5y - 3) (Ans.)
Question (4) :- Factorise using identities :-
- a) 36x² - 49b²
- b) 36y² + 36y + 9
- c) 9x⁴ - 6x²y² + y⁴
- d) a² - b² - 4ac + 4c²
- e) z⁴ - 256
- f) (x + y)² - (x - y)²
- g) (9/25)a² - (16/64)b²
Solution (a) :-
→ 36x² - 49b²
→ (6x)² - (7b)²
now we know that, (a)² - (b)² = (a - b)(a + b)
so,
→ (6x - 7b)(6x + 7b) (Ans.)
Solution (b) :-
→ 36y² + 36y + 9
taking 9 common first ,
→ 9(4y² + 4y + 1)
→ 9{(2y)² + 2 * 2y * 1 + (1)²}
now, we know that, (a² + 2ab + b²) = (a + b)² .
so,
→ 9(2y + 1)² (Ans.)
Solution (c) :-
→ 9x⁴ - 6x²y² + y⁴
→ (3x²)² - 2 * (3x²) * (y²) + (y²)²
now, we know that, (a² - 2ab + b²) = (a - b)² .
so,
→ (3x² - y²)² (Ans.)
Solution (d) :-
→ a² - b² - 4ac + 4c²
→ (a² - 4ac + 4c²) - b²
→ [(a)² - 2 * (2c) * a + (2c)²] - b²
now, we know that, (a² - 2ab + b²) = (a - b)² .
so,
→ (a - 2c)² - b²
→ (a - 2c)² - (b)²
now we know that, (a)² - (b)² = (a - b)(a + b)
so,
→ (a - 2c - b)(a - 2c + b)
→ (a - b - 2c)(a + b - 2c) (Ans.)
Solution (e) :-
→ z⁴ - 256
→ (z)⁴ - (4)⁴
→ {(z²)² - (4²)²}
now we know that, (a)² - (b)² = (a - b)(a + b)
so,
→ (z² - 4²)(z² + 4²)
again, using , (a)² - (b)² = (a - b)(a + b)
→ (z - 4)(z + 4)(z² + 16) (Ans.)
Solution (f) :-
→ (x + y)² - (x - y)²
using , (a)² - (b)² = (a - b)(a + b)
→ {(x + y) - (x - y)}{(x + y) + (x - y)}
→ (x + y - x + y)(x + y + x - y)
→ 2y * 2x
→ 4xy (Ans.)
Solution (g) :-
→ (9/25)a² - (16/64)b²
→ [{(3/5)a}² - {(1/2)b}²]
using , (a)² - (b)² = (a - b)(a + b)
→ {(3a/5) - (b/2)}{(3a/5) + (b/2)}
→ {(6a - 5b)/10}{(6a + 5b)/10}
→ (1/10)(6a - 5b)(6a + 5b) (Ans.)
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इस एक्स इक्वल टू रूट 3 प्लस वन डिवाइडेड बाय टू फाइंड द वैल्यू ऑफ एक्स क्यूब प्लस टू एक्स स्क्वायर माइनस 8 एक्स प्लस 7
https://brainly.in/question/20858452
if a^2+ab+b^2=25
b^2+bc+c^2=49
c^2+ca+a^2=64
Then, find the value of
(a+b+c)² - 100 = ...
https://brainly.in/question/16231132