Digital SATMath: AlgebraEasy
A meteorologist is tracking the temperature change during a cold front. At 8:00 AM, the temperature was 12°C. Every hour, the temperature dropped by 1.5°C. Which of the following equations represents the temperature, T, in degrees Celsius, h hours after 8:00 AM?
- AT = 1.5h + 12
- BT = 1.5 - 12h
- CT = 12h - 1.5
- DT = 12 - 1.5h
Show answer & explanationAnswer & explanation
Correct answer: D. T = 12 - 1.5h
The initial temperature is 12°C. The temperature drops by 1.5°C every hour, so we subtract 1.5h from the initial temperature to find the temperature after h hours.
Why the other options are wrong
- A. This equation incorrectly adds the temperature drop, suggesting an increase.
- B. This equation incorrectly starts with the drop rate and subtracts the initial temperature multiplied by hours.
- C. This equation incorrectly multiplies the initial temperature by hours and subtracts a constant.
Linear Equation from Word Problem
A linear equation can model situations where a quantity changes at a constant rate relative to another quantity.
- Identify the initial value (y-intercept).
- Identify the constant rate of change (slope).
- Determine if the rate is an increase (positive slope) or decrease (negative slope).
Memory trick: Words to Math: Find the Start, Find the Change, Build the Line!