To determine which of the given equations is a linear function, we can evaluate each one:
-
\( y = -12x + 78 \): This is in the form \( y = mx + b \), where \( m = -12 \) and \( b = 78 \). This is a linear function.
-
\( y = -\frac{12}{x} + \frac{7}{8} \): This equation involves \( \frac{1}{x} \), which means it's not linear (it is a rational function).
-
\( y = 2x^3 + 4 \): This involves \( x^3 \), which indicates it is a cubic function, not linear.
-
\( 2y - 5x = 9 \): We can rearrange this into the form \( y = mx + b \): \[ 2y = 5x + 9 \ y = \frac{5}{2}x + \frac{9}{2} \] This is also a linear function.
-
\( x^2 + y = 33 \): This involves \( x^2 \), which indicates it is a quadratic function, not linear.
Thus, the options that represent linear functions are:
- \( y = -12x + 78 \)
- \( 2y - 5x = 9 \) (which can be rearranged to a linear form)
Final Response: Both \( y = -12x + 78 \) and \( 2y - 5x = 9 \) are linear functions.