Question

Using identity solve the following (-a+6b+5c)^2

Answer 1

ANSWER

• Value of the above expression is a²+36b²+25c²-12ab+60bc-10ac

GIVEN:

• (-a+6b+5c)²

TO FIND:

• Value of the above expression.

FORMULA USED:

• (a+b+c)² = a²+b²+c²+2ab+2bc+2ca

SOLUTION:

= (-a+6b+5c)²

= (-a)²+(6b)²+(5c)²+2(-a)(6b)+2(6b)(5c)+2(-a)(5c)

= a²+36b²+25c²-12ab+60bc-10ac

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

Answer 2

Hello,

Using Formula :

➡(a+b+c)² = a² + b² + c² + 2ab + 2bc + 2ca ..

Solution : -

➡(-a + 6b + 5c ) ²

➡(-a)² + (6b)² + (5c)² + 2(-a) + (6b) + 2 (6b) (5c) +2(-a) (5c)

➡a² + 36b² + 25c² - 12ab + 60bc - 10 ac ..

Hope it helps u!!