Digital SATMath: AlgebraEasy
A technician is calibrating a pressure sensor. The sensor's reading, R, in kilopascals (kPa), is related to the actual pressure, P, in kPa, by the equation R = 1.05P + 3. If the sensor reads 129 kPa, what is the actual pressure?
- A125 kPa
- B128 kPa
- C132 kPa
- D120 kPa
Show answer & explanationAnswer & explanation
Correct answer: D. 120 kPa
To find the actual pressure, we substitute the sensor reading into the given equation and solve for P. This involves simple algebraic manipulation to isolate the variable.
Why the other options are wrong
- A. This might result from an arithmetic error during subtraction or division.
- B. This might result from incorrectly adding 3 instead of subtracting, or other calculation mistakes.
- C. This might result from setting P = 1.05R + 3 instead of R = 1.05P + 3.
Solving Linear Equations
The process of finding the value(s) of the variable(s) that make a linear equation true.
- Involves isolating the variable on one side of the equation.
- Uses inverse operations (addition/subtraction, multiplication/division).
- Maintains equality by performing the same operation on both sides.
Memory trick: Balance the equation to find your target variable.