Question

(3x+2y-z)^2 exapnd using suitable identify

Answer 1

Answer:

(3x+2y+z)^2 = 9x^2 +4y^2 +z^2 +12xy - 4yz - 6xz

Step-by-step explanation:

Given:

        (3x+2y-z)^2 to be expanded

Identity:

                (x+y+z)^2 = x^2 +y^2+z^2+2xy+2yz+2zx

substitute the value in this equation

(3x+2y+z)^2 = 9x^2 + 4y^2 +z^2+2(3x)(2y)+2(2y)(-z)+2(3x)(-z)

                   = 9x^2 + 4y^2 + z^2+12xy-4yz-6xz

(3x+2y+z)^2 = 9x^2 +4y^2 +z^2 +12xy - 4yz - 6xz

some more identity

• (a+b)^3 = a^3 + b^3 + 3ab(a+b)
• (a-b)^3 = a^3 - b^3 - 3ab(a-b)
• a^3 + b^3 = (a+b)(a^2 - ab + b^2)
• a^3 - b^3 = (a-b)(a^2 +ab + b^2)