Question

(3x+y)^2-(2x-y) ^2+(4x+x)^3​

Answer 1

$\bf{\underline{\underline{\bigstar\bigstar\: Solution :}}}$

$\:$

$\footnotesize{(3x+y)^2 -(2x-y)^2 +(4x+x)^3}$

$\footnotesize{= (9x^2 + y^2 + 6xy) - (2x + y)(2x - y) +(4x+x)^3}$

$\footnotesize{= (9x^2 + y^2 + 6xy) - 4x² - y² + (4x+x)^3}$

$\footnotesize{= (9x^2 + y^2 + 6xy) - 4x^2 - y^2 + 64x^3 + x^3 + 12x^3(4x + x) }$

$\footnotesize{= 9x^2 + y^2 + 6xy - 4x^2 - y^2 + 64x^3 + x^3 + 12x^3(4x + x) }$

$\footnotesize{= 13x^2 + y^2 + 6xy - 4x^2 - y^2 + 65x^3 + 12x^3 (4x + x)}$

$\footnotesize{= 9x^2 + 6xy + 65x^3 + 12x^3 (4x + x)}$

$\footnotesize{= 9x^2 + 6xy + 77x^3 (4x + x)}$

$\footnotesize{= 9x^2 + 6xy + 308x^4 + 77x^4 }$

$\footnotesize{= 9x^2 + 6xy + 385x^4}$

$\:$

$\bf{\underline{\underline{\bigstar\bigstar\: Formula \:used :}}}$

$\:$

$(a + b)^3 = a^3 + b^3 + 3ab(a + b)$

$(a + b)^2 = a^2 + b^2 + 2ab$

$(a - b)^2 = (a + b)(a - b)$