Let's work through the steps to find the solutions for each of these problems:
### 4. [tex]\(18^2\)[/tex]
To find the square of 18, we calculate:
[tex]\[ 18 \times 18 = 324 \][/tex]
Ans. 324
### 5. [tex]\(13^2\)[/tex]
To find the square of 13, we calculate:
[tex]\[ 13 \times 13 = 169 \][/tex]
Ans. 169
### 6. [tex]\(19^2\)[/tex]
To find the square of 19, we calculate:
[tex]\[ 19 \times 19 = 361 \][/tex]
Ans. 361
### 7. [tex]\(\sqrt{81}\)[/tex]
To find the square root of 81, we ask what number multiplied by itself gives 81:
[tex]\[ \sqrt{81} = 9.0 \][/tex]
Ans. 9.0
### 8. [tex]\(\sqrt{196}\)[/tex]
To find the square root of 196, we ask what number multiplied by itself gives 196:
[tex]\[ \sqrt{196} = 14.0 \][/tex]
Ans. 14.0
Therefore, the answers are as follows:
- [tex]\(18^2 = 324\)[/tex]
- [tex]\(13^2 = 169\)[/tex]
- [tex]\(19^2 = 361\)[/tex]
- [tex]\(\sqrt{81} = 9.0\)[/tex]
- [tex]\(\sqrt{196} = 14.0\)[/tex]
