Tommy solved the equation 3x-7=x/2+9 and found x=5. He then shakes his head and starts over. How did he know so quickly that he

Question

2 years ago

6

made a mistake?

1 answer:

Whitepunk [10] · Answer 1 · 2023-10-26T23:00:30+03:00

He knows he made a mistake so quickly because he substitutes 5 for x in 3x - 7 = x/2

<h3>How did he know so quickly that he made a mistake?</h3>

The equation is given as:

3x - 7 = x/2 + 9

The solution is given as:

x = 5

To quickly know he made a mistake, we substitute 5 for x in 3x - 7 = x/2 + 9

So, we have

3 * 4 - 7 = 5/2 + 9

Evaluate

12 - 7 = 2.5 + 9

Evaluate the like terms

5 = 11.5

The above equation is false.

Hence, he knows he made a mistake so quickly because he substitute 5 for x in 3x - 7 = x/2