We need to solve for x. Let's try problem b:

Let us first combine line terms. 3x and -x as well as 1 and -7 can be combined. Let's do that:

Since this is true, your answer would be:
All real numbers
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Let's solve for problem c:

Let's isolate x, so subtract 1 from both sides:

Since x can't have a coefficient, divide both sides by 3:


So, only the value of 14 would make this equation true.
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Let's try problem d:

Let's get our whole numbers on the right side. Add 1 to both sides:

Subtract 4x from the right side on both sides:

Since this is not true, your answer would be:
No solution