Answer :

To convert numbers from scientific notation to standard notation, we follow a straightforward process. Let's go through each number step-by-step:

### First Number: [tex]\( 1.98 \times 10^{4} \)[/tex]

1. Identify the base number: [tex]\(1.98\)[/tex]
2. Identify the exponent: [tex]\(4\)[/tex]
3. Since the exponent is positive ([tex]\(4\)[/tex]), it means we need to move the decimal point [tex]\(4\)[/tex] places to the right.
4. Moving the decimal point [tex]\(4\)[/tex] places to the right of [tex]\(1.98\)[/tex]:
- Moving 2 places: [tex]\(198.\)[/tex]
- Moving 2 more places: [tex]\(19800.\)[/tex]

Thus, in standard notation, [tex]\( 1.98 \times 10^{4} \)[/tex] is [tex]\( 19800.0 \)[/tex].

### Second Number: [tex]\( 4.5 \times 10^{-6} \)[/tex]

1. Identify the base number: [tex]\(4.5\)[/tex]
2. Identify the exponent: [tex]\(-6\)[/tex]
3. Since the exponent is negative ([tex]\(-6\)[/tex]), it means we need to move the decimal point [tex]\(6\)[/tex] places to the left.
4. Moving the decimal point [tex]\(6\)[/tex] places to the left of [tex]\(4.5\)[/tex]:
- Moving 1 place: [tex]\(0.45\)[/tex]
- Moving 5 more places: [tex]\(0.0000045\)[/tex]

Thus, in standard notation, [tex]\( 4.5 \times 10^{-6} \)[/tex] is [tex]\( 0.0000045 \)[/tex] or [tex]\(4.5e-06\)[/tex].

Combining these results, we get:

- [tex]\( 1.98 \times 10^{4} = 19800.0 \)[/tex]
- [tex]\( 4.5 \times 10^{-6} = 0.0000045 \)[/tex]