Question

(Y/2-Z/3)³ - (Y/2+Z/3)³ simplify​

Answer 1

x+y=7

Then:

x=7-y

And xy=12, so:

(7-y)(y)=12

7y-y²=12

y²-7y+12=0

(y-3)(y-4)=0

y=3 or 4

Then:

x=4 or 3

And:

x³+y³=3³ +4³

=27+64

=91

Another approach:

x³+y³=(x+y)(x²-xy+y²) and

x³+y³=(x+y)³-3xy(x+y)

=343–3(12)(7)

=343–252

=91 ……………..