Question

Li’s brother used the work shown to determine that he must grow at most 6 inches to be able to ride the roller coaster.

48 less-than-or-equal-to h + 42. 48 minus 42 less-than-or-equal-to h + 42 minus 42. 6 less-than-or-equal-to h.

Is this correct? Explain.

Answer 1

sample response

Explanation:

No, the work is correct, but the interpretation is not. “6 is less than or equal to h” means that h is greater than or equal to 6. He must grow at least 6 inches, not at most 6 inches.

Answer 2

It is correct

Explanation:

Given

`Height = 42\ in` ---- Missing information

`Minimum\ Height = 48\ in`

Represent the additional height (i.e. 6 inches) with h

Required

Is
`48 \le h + 42` correct

The term at most mean less than or equal to
`\le`

So, for him to grow at most 6 inches; it means that 48 inches must be less than or equal to the sum of his current height and additional height needed.

Mathematically:

`48 \le 42 + 6`

Substitute h for 6

`48 \le 42 + h`

Hence, the expression is correct.