Which of the following pairs of equations has exactly the same solution?(1 point)

Responses

3/8x=1
3
8
𝑥
=
1
and 1/3x=1/8
1
3
𝑥
=
1
8
Start Fraction 3 over 8 End Fraction x equals 1 and Start Fraction 1 over 3 End Fraction x equals Start Fraction 1 over 8 End Fraction

−3.2x=0.64

3.2
𝑥
=
0.64
and x/4=−0.05
𝑥
4
=

0.05
negative 3.2x equals 0.64 and Start Fraction x over 4 End Fraction equals negative 0.05

x/3.2=1.8
𝑥
3.2
=
1.8
and 1.8x=3.2
1.8
𝑥
=
3.2
Start Fraction x over 3.2 End Fraction equals 1.8 and 1.8x equals 3.2

−3/4x=5/2

3
4
𝑥
=
5
2
and 5/2x=−3/4

1 answer

To determine which pairs of equations have exactly the same solution, let's solve each pair step by step.

  1. First Pair:

    • Equation 1: \( \frac{3}{8}x = 1 \)
      • To isolate \( x \), multiply both sides by \( \frac{8}{3} \): \[ x = 1 \cdot \frac{8}{3} = \frac{8}{3} \]
    • Equation 2: \( \frac{1}{3}x = \frac{1}{8} \)
      • Multiply both sides by 3: \[ x = 3 \cdot \frac{1}{8} = \frac{3}{8} \]
    • Conclusion: Solutions are \( \frac{8}{3} \) and \( \frac{3}{8} \); not the same.
  2. Second Pair:

    • Equation 1: \( -3.2x = 0.64 \)
      • Divide both sides by -3.2: \[ x = \frac{0.64}{-3.2} = -0.2 \]
    • Equation 2: \( \frac{x}{4} = -0.05 \)
      • Multiply both sides by 4: \[ x = -0.05 \cdot 4 = -0.2 \]
    • Conclusion: Both have the solution \( x = -0.2 \); they are the same.
  3. Third Pair:

    • Equation 1: \( \frac{x}{3.2} = 1.8 \)
      • Multiply both sides by 3.2: \[ x = 1.8 \cdot 3.2 = 5.76 \]
    • Equation 2: \( 1.8x = 3.2 \)
      • Divide both sides by 1.8: \[ x = \frac{3.2}{1.8} \approx 1.7777 \quad (\text{not equal to } 5.76) \]
    • Conclusion: Solutions are not the same.
  4. Fourth Pair:

    • Equation 1: \( -\frac{3}{4}x = \frac{5}{2} \)
      • Divide both sides by -3/4 (or multiply by -4/3): \[ x = \frac{5}{2} \cdot \frac{-4}{3} = -\frac{10}{3} \]
    • Equation 2: \( \frac{5}{2}x = -\frac{3}{4} \)
      • Divide both sides by \( \frac{5}{2} \) (or multiply by \( \frac{2}{5} \)): \[ x = -\frac{3/4} {5/2} = -\frac{3 \cdot 2}{4 \cdot 5} = -\frac{6}{20} = -\frac{3}{10} \]
    • Conclusion: Solutions are not the same.

By evaluating each pair, the only pair with the same solution is the Second Pair:

  • \( -3.2x = 0.64 \) and \( \frac{x}{4} = -0.05 \), both yielding \( x = -0.2 \).