Respuesta :

renknee

Answer:

3x was subtracted from the left side, but 3x was subtracted from the right side. The Subtract Property of Equality states that you can subtract the same number from each side and the equation will remain true. But 3x and 3 are not the same number (unless x is 1).

x = -8/5

Step-by-step explanation:

Step 1: Simplify both sides of the equation.

  • [tex](7x+3x)+(21)=5[/tex]
  • [tex]10x + 21 = 5[/tex]

Step 2: Subtract 12 from both sides.

  • [tex]10x + 21 - 21 = 5 - 21[/tex]
  • [tex]10x = -16[/tex]

Step 3: Divide both sides by 10.

  • [tex]\frac{10x}{10} = \frac{-16}{10}[/tex]
  • [tex]x = -\frac{8}{5}[/tex]
sqdancefan

9514 1404 393

Answer:

  • 3x
  • 3
  • 1
  • x = -1.6

Step-by-step explanation:

You answer this sort of question by comparing each line to the line above to see what the differences are. In the second line, the term 3x is missing from the left side of the equal sign, and the value 5 has been changed to the value 2 on the right side. The wording of the statement you're to fill in tells you that it should read ...

  3x was subtracted from the left side, but 3 was subtracted from the right side.

  ... 3x and 3 are not the same number (unless x is 1 .)

__

The correct solution is ...

  7x +21 +3x = 5 . . . . . . given

  10x +21 = 5 . . . . . . . . . collect terms

  10x = -16 . . . . . . . . . . . subtract 21 from both sides

  x = -1.6 . . . . . . . . . . . .  divide both sides by 10

_____

Additional comment

It can often work well to "read ahead" when answering a question or series of questions. The later questions or comments often provide clues that help you understand how to answer the earlier questions.

Here, for example, it becomes clear that 3x and 3 were subtracted from the different sides of the equation. You can find that out simply by reading the rest of the statement you're to fill in. These are the answers to the questions asked in the first part of the statement.

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