Hello! :)
To solve your equation, we will first simplify both sides of the equation
-7 = -1 + x/3
-7 = -1 + 1/3x
-7 = 1/3x - 1
Next, we will flip the equation
1/3x - 1 = -7
Third, we will add 1 to both sides
1/3x - 1 + 1 = -7 + 1
1/3x = -6
Last, we will Multiply both sides by 3
3 * (1/3x) = (3) * (-6)
x = -18 (ANSWER)
That means -18 is you answer
Hope this helped you!
THEDIPER