For this case we have to by definition:
1 kg equals 1000 grams
Shark 1:
405 kg and 68 grams

Thus, shark 1 weighs 405,068 grams.
Shark 2:
324 kg and 75 grams

Thus, shark 2 weighs 324,075 grams.
Subtracting we have:

Thus, shark 1 weighs 80,993 grams more than the second.
Answer:
Shark 1 weighs 80,993 grams more than the second.
Combine like terms
-7y² + 6y² - 2y² = -3y²
4y + (-5y) - (-9y) = 4y - 5y + 9y = 8y
9 + 9 - (-2) = 9 + 9 + 2 = 20
-3y² + 8y + 20 is your answer
hope this helps
So a times 10^n where 1≤|a|<10 and n is an integer is what i learned
so
a.
234=
2.34 times 100=
2.34 times 10²
b.
0.000052=
5.2 times 1/100000=
5.2 times 10⁻⁵
c.
-220000=
-2.2 times 100000=
-2.2 times 10⁵
d. ok, so just count the spaces moved to the left
-18.2 times 10⁻¹⁵