Question

expand (x-2)³ by using standard formulae​

Answer 1

Answer:

x³+6x²+12x+8.

Step-by-step explanation: We know that (a+b)³ = a³+b³+3ab(a+b). [x+2]³ = x³+2³+3(x)(2)(x+2). [x+2]³ = x³+8+6x(x+2).

Answer 2

Your Answer:

The standard Formula of finding the cube of sum of two variables is

(x+y)³=x³+y³+3xy(x+y)

So,

(x+2)³

=x³ + 2³ + 3(x)(2)(x+2)

=x³ + 8 + 6x(x+2)

=x³ + 8 + 6x² +12x

=x³ + 6x² + 12x + 8

So, the expanded form of (x+2)³ is x³+6x²+12x+8

Additional:

The another Formula two find the cube of sum of two variable is

(x+y)³=x³+y³+3x²y+3xy²

Some, other formulas are

• (x+y)²=x²+y²+2xy
• (x-y)²= x²+y²-2xy
• (x+a)(x+b)= x²+(a+b)x+ab
• x³+y³=(x+y)(x²+y²-xy)
• x³-y³=(x-y)(x²+y²+xy)

Concept used:-

Multiplication of numbers

Addition of Numbers

Cubing of Number

Opening of Brackets