Question

1. solving $ad + be = cf$ for $d$ starts with:

a. adding $be$ to both sides
b. multiplying by $a$
c. subtracting $be$ from both sides
d. dividing by $a$

Explanation:

Step1: Isolate term with $d$

To solve for $d$, first eliminate the term without $d$ from the left side. We do this by subtracting $be$ from both sides of the equation:
$ad + be - be = cf - be$

Step2: Simplify the equation

After subtraction, we get:
$ad = cf - be$
(The next step would be dividing by $a$, but the question asks for the starting step)

Answer:

c. Subtracting $be$ from both sides