How much is 21a3 -17a2 less than 89a3 - 64a2 + 6a + 16 ?

1.	How much is 21a3 -17a2 less than 89a3 - 64a2 + 6a + 16 ?
Answer» Required expression is 89a³ -64a²+6a+16-(21a³ -17a²) = 89a³ -64a²+6a+16 -21a³ + 17a² On combining the like terms, = 89a³ -21a³ – 64a² +17a² + 6a+16 = 68a³ -47a² + 6a+16 So,21a³ -17a² is 68a³-47a² + 6a+16 less than 89a³ -64a²+6a+16.

Answer»

Required expression is

89a³ -64a²+6a+16-(21a³ -17a²)

= 89a³ -64a²+6a+16 -21a³ + 17a² On combining the like terms,

= 89a³ -21a³ – 64a² +17a² + 6a+16

= 68a³ -47a² + 6a+16

So,21a³ -17a² is 68a³-47a² + 6a+16 less than 89a³ -64a²+6a+16.

Discussion