Final answer:
The correct expression representing a in terms of b is Option 1: a = 2b - 3. Therefore,the correct Option is Option 1: a = 2b - 3
Step-by-step explanation:
To find the expression for a in terms of b, we can use the given system of equations:
![\[2a = 4c \quad \text{(1)}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/5cbdh657zz4scuctof2qjsli1tel4v7316.png)
![\[12b = 3c - 15 \quad \text{(2)}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/1j5jymw515xaxiwiic568c4jkptnrffq66.png)
First, let's isolate c in terms of a from equation (1):
![\[a = 2c \quad \text{(3)}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/t1jnp6xn1vbaqpjopwvsg6jk173z6vphgk.png)
Now, substitute equation (3) into equation (2) to eliminate c:
12b = 3(2a) - 15
12b = 6a - 15
Next, isolate a in terms of b:
![\[a = (12b - 15)/(6)\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/6lpl2gfkw2zte3xgzk91iz3ndqiwo02ht3.png)
a = 2b - 3
Comparing this with the given options, the correct expression is Option 1: (a = 2b - 3).
Therefore,the correct Option is Option 1: a = 2b - 3