Answer:
The first option (5.7km)
Step-by-step explanation:
Since we have a right angle triangle and we know two of its sides we can easily find out the thirds side (the value of d) by using the Pathagoras Theorem. In our case 7 and d are our legs and the hypotenuse is equal to 9, so...
(Based on the Pathagoras Theorem)



d ≈ 5.7km
There for aproximate distance across the lake is equal to 5.7km
Percent = 75%
base = unknown ...the base is the number that follows " of "
amount = 30
Let's look at an example:
2.24 x 21.6

Do normal multiplication and get
48384 This is not correct, until we put the decimals in. To know how to do this, count the number of decimal spaces from the factors. In 2.24, there are 2, because .24. In 21.6 there are 1 because of .6. This mean three places, so 48384 becomes
48.384
~theLocoCoco
1. 6+ -35 = -29
2. -29+ 6 = -35
1. 37 + -33 = 4
2. -33 + 4 = 37