Answer:
(f + g)(x) = – 3x^2 + 5x - 8
Step-by-step explanation:
(f + g)(x) = f(x) + g(x)
= 5x^2 + 9x – 4 + (– 8x^2 – 3x – 4)
= 5x^2 + 9x – 4 – 8x^2 – 3x – 4
Combine
= – 3x^2 + 5x - 8
4 is what is knows as the factorial of 4.
4=4*3*2*1=24
Answer: He made $90 last week.
Assumption :
Let, Luis made $X last week.
He made $72 this week which is 80% of $X that he made last week
⇒ X * 80% = 72
⇒ X * 80/100 = 72
⇒ X = (72 * 100)/80
⇒ X = 90
Therefore, he made $90 last week.
To remember :
While solving this type of problems, be careful to understand which one of last time and current time is not given; just assume that one and input other conditions, the problem will be solved.
Answer: This is a type of Synthesis reaction.
Explanation:
- Synthesis reaction is a type of chemical reaction in which two or more substances combine to form a single substance.

- Decomposition reactions are a type of chemical reactions in which a substance breaks down into two or more substances.

- Combustion reaction is a type of chemical reaction in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water.

For the given reaction:

Here, 2 substances are combining together to form a single substance. Hence, it is considered as a synthesis reaction.
0.9 as a fraction is:

What place is the '9' in? It's in the tenth place.
0.9 can be said as

Nine

tenths

=