Question

if a+1=-2b show that 1+a^3+8b^3=6ab

Answer 1

Step-by-step explanation:

a+1=-2b

a+2b=-1

cubing both side

(a+2b)^3=-1^3

a^3+(2b)^3 + 3*a*2b(a+2b) =-1

a^3+8b^3 +6ab*-1=-1

a^3+8b^3-6ab=-1

1+a^3+8b^3= 6ab

proved

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