Answer:
[tex]\frac{64}{49}[/tex]
Step-by-step explanation:
As we can see the given expression as three complex parts and all are being multiplied.
Lets simplify each part separately and then multiply all of them in the end
Part1
[tex](\frac{8.4.2}{8.7})^{2} [/tex]
Cancelling 8 in numerator with 8 in denominator
[tex](\frac{4.2}{7})^{2}[/tex]
[tex](\frac{8}{7})^{2}[/tex]
[tex]\frac{64}{49}[/tex]
Part2
[tex](\frac{8^{0} }{7^{-3} })^{3}[/tex]
simpliying
[tex](\frac{1}{7^{-3} })^{3}[/tex]
[tex]({7^{3} })^{3}[/tex]
[tex]7^{9}[/tex]
Part3
Third part is [tex] 7^{-9}[/tex], and it does not need to be further simplified
Now multiplying all the three parts
[tex]\frac{64}{49}.7^{9}.7^{-9}[/tex]
[tex]\frac{64}{49}.7^{9-9}[/tex]
[tex]\frac{64}{49}.7^{0}[/tex]
[tex]\frac{64}{49}.1[/tex]
[tex]\frac{64}{49}[/tex]
So our final answer is [tex]\frac{64}{49}[/tex]
