-7(3x-1)
Let’s distribute that.
-7 x 3x = -21x
-7 x -1 = 7
Let’s rewrite, using the distributed numbers I just got.
91 = -21x + 7
Now, let’s solve for x.
91 -7 = -21x + 7 -7
(Remember, whatever you do on one side you do on the other)
84=-21x
84/-21=-21x/-21
-4=x
Solution : x=-4