Sovi.AI - AI Math Tutor

Scan to solve math questions

QUESTION IMAGE

define a variable, write an inequality, and solve each problem. check y…

Question

define a variable, write an inequality, and solve each problem. check your solution.

  1. seven more than a number is less than or equal to -18.
  2. twenty less than a number is at least 15.
  3. a number plus 2 is at most 1.
  4. one eighth of a number is less than or equal to 3.
  5. negative twelve times a number is no more than 84.
  6. eight times a number is at least 16.

Explanation:

Response

Let's solve each problem one by one. We'll start with problem 61.

Problem 61: Seven more than a number is less than or equal to -18.

Step 1: Define the variable

Let \( x \) be the number.

Step 2: Write the inequality

"Seven more than a number" means \( x + 7 \). "Is less than or equal to -18" gives the inequality \( x + 7 \leq -18 \).

Step 3: Solve the inequality

Subtract 7 from both sides: \( x + 7 - 7 \leq -18 - 7 \), so \( x \leq -25 \).

Step 4: Check the solution

Let's pick a number less than or equal to -25, say \( x = -26 \). Then \( -26 + 7 = -19 \), and \( -19 \leq -18 \) is true. Another check: \( x = -25 \), \( -25 + 7 = -18 \), and \( -18 \leq -18 \) is also true.

Problem 62: Twenty less than a number is at least 15.

Step 1: Define the variable

Let \( x \) be the number.

Step 2: Write the inequality

"Twenty less than a number" is \( x - 20 \). "Is at least 15" means \( x - 20 \geq 15 \).

Step 3: Solve the inequality

Add 20 to both sides: \( x - 20 + 20 \geq 15 + 20 \), so \( x \geq 35 \).

Step 4: Check the solution

Pick \( x = 35 \): \( 35 - 20 = 15 \), and \( 15 \geq 15 \) is true. Pick \( x = 36 \): \( 36 - 20 = 16 \), and \( 16 \geq 15 \) is true.

Problem 63: A number plus 2 is at most 1.

Step 1: Define the variable

Let \( x \) be the number.

Step 2: Write the inequality

"A number plus 2" is \( x + 2 \). "Is at most 1" gives \( x + 2 \leq 1 \).

Step 3: Solve the inequality

Subtract 2 from both sides: \( x + 2 - 2 \leq 1 - 2 \), so \( x \leq -1 \).

Step 4: Check the solution

Pick \( x = -1 \): \( -1 + 2 = 1 \), and \( 1 \leq 1 \) is true. Pick \( x = -2 \): \( -2 + 2 = 0 \), and \( 0 \leq 1 \) is true.

Problem 64: One eighth of a number is less than or equal to 3.

Answer:

s:

  1. \( x \leq -25 \)
  2. \( x \geq 35 \)
  3. \( x \leq -1 \)
  4. \( x \leq 24 \)
  5. \( x \geq -7 \)
  6. \( x \geq 2 \)