Question

brainly teacher please help me to find out from this all questions please​

Answer 1

Answer:

1 answer- (3x+4)(7x-9)

multiply 3x by 7 and 9 both and 4 by 7x and 9

=21x-27x+28x-36

=21x+x-36

2 answer-(x²+y)(x²+x)

Answer 2

$\underline{\underline{\bf\red{Concept-}}}$

$\sf (a +b)(c+d) = a(c+d) + b(c+d)$

$\quad\quad\quad\quad \text{(by \: distribution) }$

$\sf (a+b) (c+d) = ac +ad + bc + bd$

$\underline{\underline{\bf\green{Solution -}}}$

$\sf (a) (3x +4) (7x-9)$

$\sf (3x)(7x) + (3x)(-9) + (4)(7x) +(4)(-9)$

$\sf 21x^2 +(-27x )+ 28x +(-36)$

$\sf 21x^2 -27x + 28x -36$

$‎ \sf 21x^2 +x -36$

$\sf (b)(x^2+y)(x^2+x)$

$\sf (x^2)(x^2) + (x^2)(x)+(y)(x^2)+(y)(x)$

$\sf x^4 + x^3+x^2y +xy$

$\sf (c)(3a^2+b)(2a^2+4b^2)$

$\sf (3a^2)(2a^2) +(3a^2)(4b^2)+(b)(2a^2)+(b)(4b^2)$

$\sf 6a^4 + 12a^2b^2 +2a^2b + 4b^3$

$\sf (d) (3x^2 -y^2)(2x^2+3y^2)$

$\sf (3x^2)(2x^2) +(3x^2)(3y^2) + (-y^2)(2x^2) + (-y^2)(3y^2)$

$\sf 6x^4 + 9x^2y^2+(-2x^2y^2)+(-3y^4)$

$\sf 6x^4 + 9x^2y^2-2x^2y^2-3y^4$

$\sf 6x^4 + 7x^2y^2-3y^4$

$\sf (e) (5x^2-2y^2) (2x^2-5y^2)$

$\sf (5x^2)(2x^2) +(5x^2)(-5y^2)+(-2y^2)(2x^2)+(-2y^2)(-5y^2)$

$\sf 10x^4+(-25x^2y^2 )+(-4x^2y^2) +10y^4$

$\sf 10x^4-25x^2y^2 -4x^2y^2 +10y^4$

$\sf 10x^4-29x^2y^2 +10y^4$

$\sf (f) (x^4-y^4)(x^2-y^2)$

$\sf (x^4)(x^2)+(x^4)(-y^2)+(-y^4)(x^2)+(-y^4)(-y^2)$

$\sf x^6 +(-x^4y^2)+(-x^2y^4)+y^6$

$\sf x^6 -x^4y^2-x^2y^4+y^6$