Question

Savannah buys a $40 gift card to her favorite smoothie shop. Each smoothie costs $4. She wants to have at least $10 left on her card at the end of this month. The inequality below relates x, the number of smoothies she could buy between now and the end of this month with her gift card balance.

40 minus 4 x greater-than-or-equal-to 10

Which best describes the number of smoothies Savannah can buy?
She can buy from 0 to 3 smoothies, but no more.
She can buy from 0 to 7 smoothies, but no more.
She can buy from 0 to 8 smoothies, but no more.
She can buy from 0 to 10 smoothies, but no more.

Answer 1

To solve the inequality \( 40 - 4x \geq 10 \), we need to isolate \( x \).

1. Start by subtracting 40 from both sides:
\[
-4x \geq 10 - 40
\]
\[
-4x \geq -30
\]

2. Next, divide both sides by -4. Remember that dividing by a negative number reverses the inequality sign:
\[
x \leq \frac{-30}{-4}
\]
\[
x \leq 7.5
\]

Since \( x \) represents the number of smoothies Savannah can buy, it must be a whole number. Therefore, the maximum number of smoothies Savannah can buy is 7.

Thus, the number of smoothies she can buy is from 0 to 7, but no more.

The best description is:
**She can buy from 0 to 7 smoothies, but no more.**