First you find like terms: The like terms in this equation would be -4x and -3x. Another set of like terms would be -7 and 4. So first what you do is add -4x and -3x to get -7x. Then you add -7 with 4 which is -3. So now write the equation as -7x -3 = 25. now Add 3 to both sides. so now the equation looks like -7x = 28 now divide -7 on both sides. SO now your final answer should be x = -4