Answer:
20% increase
Step-by-step explanation:
All you have to do is divide 72 by 90n and it will give you .8, move the decimal two places to the right to give you 80 and subtract 80 from 100 to get 20
B is equal to 154 degrees. we know this cause half of the circle equals 180 and if you subtract a (26) from 180 you get 154
Let x gallons be the amount of pure antifreeze that should be added to the 30% solution to produce a solution that is 65% antifreeze. Then the total amount of antifreeze solution will be x+3 gallons.
There are 30% of pure antifreeze in 3 gallons of solution, then
3 gallons - 100%,
a gallons - 30%,
where a gallons is the amount of pure antifreeze in given solution.
Mathematically,

Now in new solution there will be x+0.9 gallons of pure antefreeze.
x+3 gallons - 100%,
x+0.9 - 65%
or

Answer: he should add 3 gallons of pure antifreeze.
Answer:
Commutative Property
Step-by-step explanation:
It looks like Associative property which is when you change the GROUP, but actually it’s commutative because it didn’t change any numbers in the group, just the order of where they were.
Associative: (25 + 19) + 15 = (15 + 19) + 25
Commutative: (25 + 19) + 15 = (19 + 25) + 15
It didn’t change the numbers, only the order. Therefore, it would be commutative property
Alright, we're in the home stretch here :) All you need to remember is that i² = -1. Otherwise, it is the same as FOIL
(3-2i)(1+7i)
3-2i+21i-14i² ← Replace the i² with -1, then simplify like numbers
3+19i+14
17+19i or C