+91-87964 74404
FlagBACK
Question icon
Grade 99 grade maths

Without actually calculating the cubes find the value of (-1)3​+(-2)3​+(-3)​3​+(-4)3​+​2(5)3​. Also say the identity used.

Profile image of sushil
9 Years agoGrade 9
Answers icon

3 Answers

Profile image of Arun
9 Years ago
(-1)^3​+(-2)^3​+(-3)^​3​+(-4)^3​+​2(5)^3
[(-1)^3​+(-4)^3​+​(5)^3​] + [(-2)^3​+(-3)​^3​+(5)^3​]
we know that when a+ b+ c = 0 then a^3 +b^3 +c^3 =  3* a*b*c
3[( –1)( –4)(5)] + 3[( –2)( –3)(5)]
60 + 30
 =150    answer
hope it helps
Profile image of Arun
9 Years ago
sorry it was
60 + 90 = 150 (answer)
i wrote that by mistake.
hope you understand
you can do more question on similair pattern
Profile image of rasheed
8 Years ago
we know that a+b+c = 0 then a3+b3+c3 = 3abc
 
(-1)3 + (- 4)3 + (5)3 = 3(-1)(-4)(5)  = 60
(-2)3 + (-3)3 + (5)3   = 3(-2)(-3)(5) = 90
= 60 + 90 = 150

Other Related Questions on 9 grade maths

question mark

What are the differences between similar triangles and congruent triangles?

9 grade maths
1 Answer Available

Last Activity: 1 Year ago

question mark

What are Armstrong numbers?

9 grade maths
1 Answer Available

Last Activity: 1 Year ago

question mark

All real numbers are rational numbers.

A) True

B) False

9 grade maths
1 Answer Available

Last Activity: 1 Year ago

question mark

The L.C.M of the smallest 2 digit composite number and the smallest composite number is:

  • (a) 12
  • (b) 4
  • (c) 20
  • (d) 44
9 grade maths
1 Answer Available

Last Activity: 1 Year ago

question mark

Are all natural numbers also whole numbers?

9 grade maths
1 Answer Available

Last Activity: 1 Year ago