Answer as a fraction: 9/2
Answer in decimal form: 4.5
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Work Shown
x = some number
2x = twice that number
2x+3 = add on three
2x+3 = 12 is the equation to set up
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Let's solve for x. We follow PEMDAS in reverse to undo each thing we did to x, so we can isolate it. The last thing we did was "add 3", so we undo this by subtracting 3 from both sides.
Then we undo the "multiply by 2" operation when we divide both sides by 2.
Here are the steps:
2x+3 = 12
2x+3-3 = 12-3 .... subtract 3 from both sides
2x = 9
2x/2 = 9/2 ..... dividing both sides by 2
x = 9/2 is the answer as a fraction
x = 4.5 is the answer in decimal form. This value is exact without any rounding done to it.
Feel free to ask any further questions if you're still stuck.