Question

a/3=b/5=4a+5b/? fill in the blanks​

Answer 1

Answer:

Using the identity: (a+b)3=a3+b3+3a2b+3ab2

Therefore,

(4a+5b)3=(4a)3+(5b)3+(3×(4a)2×5b)+(3×4a×(5b)2)=64a3+125b3+(15b×16a2)+(12a×25b2)

=64a3+125b3+240a2b+300ab2

Hence, (4a+5b)3=64a3+125b3+240a2b+300ab2.