To solve the inequality \( -15 < -3c \), we need to isolate \( c \).
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Start with the original inequality: \[ -15 < -3c \]
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To isolate \( c \), divide both sides by \(-3\). Remember that dividing or multiplying both sides of an inequality by a negative number reverses the inequality sign: \[ \frac{-15}{-3} > c \] This simplifies to: \[ 5 > c \]
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This can be rewritten as: \[ c < 5 \]
Solution
The solution to the inequality is: \[ c < 5 \]
Graphing the Solution
To graph the inequality \( c < 5 \):
- Draw a number line.
- Place an open circle on the number \( 5 \) to indicate that \( 5 \) is not included in the solution set.
- Shade to the left of \( 5 \) to indicate all numbers less than \( 5 \).
Checking the Solution
To verify the solution, we can test points:
- For \( c = 4 \), check the original inequality: \[ -15 < -3(4) \quad \Rightarrow \quad -15 < -12 \quad \text{(true)} \]
- For \( c = 6 \), check the original inequality: \[ -15 < -3(6) \quad \Rightarrow \quad -15 < -18 \quad \text{(false)} \]
This confirms that \( c < 5 \) is indeed the correct solution.