Two Ways to Solve an EquationDate: 1/23/96 at 21:28:24 From: Anonymous Subject: MATH X + 3 = 7 Date: 3/4/96 at 22:46:2 From: Doctor Jodi Subject: Re: MATH Hi there! I can think of two ways to solve the problem you sent us - x + 3 = 7 One way is to think about what number, added with 3, will give you 7. I can make a guess and then check my answer. If I guess 5, I find out that 5 + 3 = 8, so that can't be the answer. Then I try 4, and check to see: 4 + 3 = 7, yes, 4 is the answer. The other way uses the idea that addition and subtraction are opposites. Does that make sense? If I add 5 to 3, I get 8. I can get 3 back by subtracting the same number I added: 8 - 5 = 3 So if I take your equation, x + 3 = 7, and subtract 3 from each side, I get: x + 3 = 7 -3 -3 ___________ x = 4 Does this make sense? Write back if you have more questions. -Doctor Jodi, The Math Forum |
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