Solve the following inequality. Justify each step.

negative 4 less than or equals StartFraction t Over 7 EndFraction
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Part 1
What is the​ solution?
  
t greater than or equals minus 28
​(Simplify your answer. Type an​ inequality.)
Part 2
Select all properties of inequalities used to obtain the solution.
A.
Addition property of inequality
B.
Subtraction property of inequality
C.
Multiplication property of inequality
D.
Division property of inequality

1 answer

To solve the inequality \(-4 \leq \frac{t}{7}\), let's follow the steps clearly and justify each step taken:

Step 1: Eliminate the fraction

To eliminate the fraction, we will multiply both sides of the inequality by 7. However, since we are multiplying by a positive number, the direction of the inequality remains the same.

\[ -4 \times 7 \leq \frac{t}{7} \times 7 \]

This simplifies to:

\[ -28 \leq t \]

or equivalently:

\[ t \geq -28 \]

Final Solution

So, the solution to the inequality is:

\[ t \geq -28 \]


Part 2: Properties of Inequalities Used

In the solution process, we used the following property of inequalities:

D. Division property of inequality

This is because we were effectively dividing both sides by 7 to isolate \(t\), although in this specific case, we multiplied instead of dividing to eliminate the fraction. The division property states that if \( a \leq b \) and \( c > 0 \), then \( \frac{a}{c} \leq \frac{b}{c} \).

Since we multiplied by a positive number, other properties were not necessary for this case (we did not need addition or subtraction properties).

Therefore:

  • The correct property used in the manipulation is: D. Division property of inequality