Question

y^4 - 81 use identity (a-b) (a+b) ​

Answer 1

Answer:

(i) Algebraic Expression

• Terms are formed by the product of variables and constants, e.g.

–3xy, 2xyz, 5x2, etc.

• Terms are added to form expressions, e.g. –2xy + 5x2.

• Expressions that contain exactly one, two and three terms are

called monomials, binomials and trinomials, respectively.

• In general, any expression containing one or more terms with non-

zero coefficients (and with variables having non-negative exponents)

is called a polynomial.

• Like terms are formed from the same variables and the powers of

these variables are also the same. But coefficients of like terms

need not be the same.

• There are number of situations like finding the area of rectangle,

triangle, etc. in which we need to multiply algebraic expressions.

• Multiplication of two algebraic expressions is again an algebraic

expression.

• A monomial multiplied by a monomial always gives a monomial.

• While multiplying a polynomial by a monomial, we multiply every

term in the polynomial by the monomial using the distributive

law a ( b + c) = ab + ac.

Answer 2

Answer:

y=±3,y=±3i

Step-by-step explanation:

As a^2-b^2=(a-b)(a-b)

y^4 - 81=(y^2-9)(y^+9)

y=±3, y=±3i [i=√-1]