Each step in a procedure to solve this equation is shown.



Equation: 5x−7=3(x+1)

Step 1: 5x−7=3x+3

Step 2: 2x−7=3

Step 3: 2x=−4

Step 4: x=−2



In which step is the first error made?




a. from the original equation to step 1


b. from step 1 to step 2


c. from step 2 to step 3


d. from step 3 to step 4