Your equation would be 2x - 12 + 3x - 15 = 23
Combine like terms and solve for x
Answer:

Step-by-step explanation:
Given that,
Mass of a certain material, m = 71 pounds
Since, 1 ton = 2000 pounds
71 pounds = 0.0355 ton
Volume of the material, V = 2.5 gallons
Since, 1 m³ = 264.172 gallon
2.5 gallon = (2.5/264.172 ) m³
Density,

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