Answer:
Step-by-step explanation:
A complex number is a number that contains a real part and an imaginary one .
Mathematical expression : a+bi xhera a and b are real numbers and i the solution of an equation like x²) -1 ..
<span>A water tank is 1/8 full. The tank is 3/4 full when 42 gallons are added to the tank. How much water was originally in the tank? (I rewrote it, your wording was messed up)
3/4 = 6/8
1/8 + 6/8 = 7/8 = 42 gallons
42 divided by 8 = 5 1/4
So, the answer is 5 1/4. The tank originally 5.25 gallons of water.</span>
Answer:

Step-by-step explanation:
<u>Sequential Operations
</u>
Mathematical operations can be done in sequence or in batches if they are of the same type. For example, we can add many terms in one single operation, but we cannot add and multiply in one go, because there are priorities when dealing with products and sums. Same happens with powers.
In our problem we are required to perform a sequence of operations like follows
Add s to t:

Add the result to r

Raise what you have to the 7th power

This is the final result
Step-by-step explanation:
are you sure you wrote the problem here correctly ?
because the distance will be 40km after less than half an hour just by the first car driving. way before the second car even starts.
to be precise, it would be after 60 minutes × 40 / 90
(= how many minutes of an hour are needed to reach 40km while going 90km/h) :
60 × 40 / 90 = 60 × 4 / 9 = 20 × 4 / 3 = 80/3 = 26.67 minutes.
but maybe the question was about 400km distance between the two cars.
so, the first car goes 90km/h for 2 hours.
at that moment it will be 2×90=180km ahead.
that would mean that 220km are still missing for the 400km assumption.
with each hour driving the first car makes 20km more than the second car.
to build up 220km that way would require
220/20 = 11 hours.
plus the 2 original head start hours this would make 13 hours as overall answer.