Answer: 
Step-by-step explanation:
1. To write the number given in the problem (4,498,000,000) in scientific notation you must write it in the following form:

2. The decimal point must be written after the first digit and the exponent b must be positive and indicates the number of times the decimal point is move to the right. Therefore, you have:

The answer is:
545>322
540 <997
X=6 and x=-8
To solve this, you would treat x-6=0 as one equation, you add 6 to each side to get rid of -6, hence you would get x=6.
Same goes for x+8=0, subtract 8 from each side to get rid of the +8, then you get x=-8
10)
180-60-90 = 30
30+2x=180
30-30+2x=180-30
2x=150
2x/2 = 150/2
x=75
12) B . <CBA ≈ <CDA