Question

Find the value of x.

1. x + 3 = –9
2. x – 1 = 4
3. 4x = –12
4. x/3 = 2
5. 2x – 6 = 14
6. 2 + 1/4x = –3
7. 3(x + 1) = 21

Answer 1

1.: x = -12

2.: x = 5

3.: x = -3

4: x = 6

5.: x = 10

6.: x = -20

7.: x = 6

Explanation:

1.: Step 1: Subtract 3 from both sides to find x:

(x + 3 = -9) - 3

x = -12

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2.: Step 1: Add 1 to both sides to find x:

(x - 1 = 4) + 1

x = 5

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3. Step 1: Divide both sides by 4 to find x:

(4x = -12) / 4

x = -3

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4.: Step 1: Multiply both sides by 3 to find x:

(x / 3 = 2) * 3

x = 6

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5.: Step 1: Add 6 to both sides:

(2x - 6 = 14) + 6

2x = 20

Step 2: Divide both sides by 2 to find x:

(2x = 20) / 2

x = 10

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6.: Step 1: Subtract 2 from both sides:

(2 + 1/4x = -3) - 2

1/4x = -5

Step 2: Divide both sides by 1/4 to find x:

• To divide by a fraction, we multiply by the reciprocral.
• The reciprocral of 1/4 is 4/1, which is simply 4.

Thus, we can multiply both sides by 4 to find x:

(1/4x = -5) * 4

x = -20

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7.: Step 1: Multiply the three to the terms in the parentheses on the left-hand side:

(3 * x) + (3 * 1) = 21

3x + 3 = 21

Step 2: Subtract 3 from both sides:

(3x + 3 = 21) - 3

3x = 18

Step 3: Divide both sides by 3 to find x:

(3x = 18) / 3

x = 6