Question

Factorise 25x³y³-49xy

Answer 1

we have to take 25 as 5 to the power 2 and -49 as -7 to the power 2

Answer 2

ANSWER:

• Factorisation of the above expression is xy(5xy+7)(5xy-7)

GIVEN:

• P(x) = 25x³y³ - 49xy

TO FIND:

• Factorise the above expression.

Formula used:

• a²-b² = (a+b)(a-b)

SOLUTION:

= 25x³y³ - 49xy

= xy (25x²y²-49)

= xy [(5xy)²-(7)²]

= xy(5xy+7)(5xy-7)

Factorisation of the above expression is xy(5xy+7)(5xy-7)

NOTE:

Some important formulas:

(a+b)² = a²+b²+2ab

(a-b)² = a²+b²-2ab

(a+b)(a-b) = a²-b²

(a+b)³ = a³+b³+3ab(a+b)

(a-b)³ = a³-b³-3ab(a-b)

a³+b³ = (a+b)(a²+b²-ab)

a³-b³ = (a-b)(a²+b²+ab)

(a+b)² = (a-b)²+4ab

(a-b)² = (a+b)²-4ab