Answer:
1. -2
2. 18
3. -2
Explanation:
In the following explanations "x" is a variable which represents "a number" given in the problems.
1. You can set up a simple equation " x + 7 = 5 " because you are increasing a number to get the answer. From there you can subtract 5-7 and you'll get -2, the answer to the first one.
2. This time the number is decreased by 6, and the answer is 12. Since it's being decreased, you'll set up the equation like this: " x - 6 = 12 ". For this problem you can do 12 + 6 = 18, which is your answer.
3. A number "added" to -3 is -5. The number following 'is' will almost always be the answer you're looking for, so we can do x + (-3) = -5 . From there just add 3 to each side, and you'll get -2 + (-3) = -5.
If you take one thing away from this, let it be the following:
The methods that I used do work, but something I'd suggest trying in the future is carrying over the same number to the other side of the equation.
If you're struggling on these problems, this might help.
The way this works is simple, lets say you have this equation:
x + 5 = 10
The best and most efficient way of solving this problem is by taking a number from one side, and moving it to the other side. It seems confusing at first, but isn't all that hard once you figure it out. So for this problem:
x + 5 = 10
- 5 -5
Now you only have 'x' on the left side of the equation. This is the end goal. Once you get x on one side of the equation, the answer tends to be on the other side.
So:
x + 5 = 10
- 5 -5
x + 0 = 5 <- this is what you want.
x = 5
Hope this helps, and hope you learned more from this then an hour and a half at school :P