Question 66181
–3(10x – 3) + 10(3x – 3) = x – 7<br>

using the distributive law we get:
-30x + 9 + 10x - 30 = x - 7<br>

now combining like terms:
-20x - 21 = x - 7<br>

now adding 20x to both sides:
-21 = 21x - 7<br>

now adding 7 to both sides:
-14 = 21x<br>

now dividing boths sides by 21:
-2/3 = x