-3x + 7 = -1
-3x = -8
x = 8/3
In order to solve for x, you must isolate the variable. Because -1 and 7 are like terms, use inverse operations to subtract 7 from both sides. Then, divide both sides by -3. This should get you x = 8/3, which can’t be reduced any more (unless you convert to decimal, which is about 2.666666…) Feel free to comment any questions you have! Always happy to help :)