Answer :

To evaluate the expression [tex]\( 8a - 1 + 0.5b \)[/tex] given [tex]\( a = \frac{1}{4} \)[/tex] and [tex]\( b = 1 \)[/tex], follow these steps:

1. Substitute the given values into the expression:
[tex]\[ 8 \left( \frac{1}{4} \right) - 1 + 0.5 (1) \][/tex]

2. Evaluate each term separately:

- For the term [tex]\( 8 \left( \frac{1}{4} \right) \)[/tex]:
[tex]\[ 8 \cdot \frac{1}{4} = 2 \][/tex]
- For the term [tex]\( 0.5 \cdot 1 \)[/tex]:
[tex]\[ 0.5 \cdot 1 = 0.5 \][/tex]

3. Combine the evaluated terms together:
[tex]\[ 2 - 1 + 0.5 \][/tex]

4. Perform the arithmetic operations:
- First, subtract:
[tex]\[ 2 - 1 = 1 \][/tex]
- Then, add:
[tex]\[ 1 + 0.5 = 1.5 \][/tex]

Thus, the value of the expression [tex]\( 8a - 1 + 0.5b \)[/tex] when [tex]\( a = \frac{1}{4} \)[/tex] and [tex]\( b = 1 \)[/tex] is [tex]\( 1.5 \)[/tex].