Given the equation solved by Morgan, Dakota and Taylor expressed as 7x+5x+1=73, to get the value of x, the valid steps are as shown;
7x+5x+1=73
take the sum of 7x and 5x
12x+ 1 = 73
subtract 1 from both sides
12x+1-1 = 73-1
12x = 72
Divide both sides by 12
12x/12 = 72/12
x = 6
Based on the calculation above, the students with invalid first step is Dakota.
<em>Dakota added 5x with 1 to get 6x which is an invalid step because 1 is not attached to a variable x. A function cannot be added to a constant hence making his first step invalid.</em>
As you can see, Taylor failed to add 1 to her equation. This ruins the whole first step. She also used 72 instead of 73 for the answer. Taylor is incorrect.