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22 votes
22 votes
The sum of x and 3 is the same as the 5 less than 3x. Find x.​

User Chris Trudeau
by
3.1k points

1 Answer

17 votes
17 votes

Answer:

x = 4

Explanation:

"Sum" means add. "Less than" means subtract. "The same" means equal. Set the equation:

x + 3 = 3x - 5

Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Subtract 3x and 3 from both sides of the equation:

x (-3x) + 3 (-3) = 3x (-3x) - 5 (-3)

x - 3x = -5 - 3

Simplify. Combine like terms:

-2x = -8

Isolate the variable, divide -2 from both sides of the equation:

(-2x)/-2 = (-8)/-2

x = -8/-2 = 4

Check: Plug in 4 for x in the equation:

x + 3 = 3x - 5

4 + 3 = 3(4) - 5

7 = 12 - 5

7 = 7 (True).

x = 4 is your answer.

~

User Soumya Behera
by
2.7k points
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