Assessment and Learning in Knowledge Spaces (ALEKS) Basic Math Placement Practice Test

In the equation \( y = ax + b \), the y-intercept is the point where the line crosses the y-axis. This occurs when the value of \( x \) is zero. To find the y-intercept, one can substitute \( x = 0 \) into the equation. When you do this, the equation simplifies to \( y = a(0) + b \), which further reduces to \( y = b \).

Thus, the y-intercept is indeed represented by the value of \( b \), meaning that at the point \( (0, b) \), the line intersects the y-axis. This understanding is crucial for graphing linear equations and interpreting their characteristics.

The other options discuss aspects of the equation but do not provide the correct determination of the y-intercept. The value of 'a' is the slope of the line and does not provide any information about where the line crosses the y-axis. Similarly, the notion of calculating the y-intercept by subtracting 'a' from 'b' is not appropriate, as it does not correspond to the standard method of finding the y-intercept in a linear equation.