How do you solve: 11a=18a+21 ?
11a = 18a + 2111a - 18a = - 18a + 21-7a = 217a = -21a = -21/ 7a = -3
Ok, the points is to isolate the variable "a". First, you subtract 18a from both sides to remove the 18a from the right side, ending up with -7a = 21. Dividing both sides by -7, you will end up with a = -3. Answer: a = -3