Final answer:
y cannot be directly solved from the given expression without an equation. The linear equation y = 9 + 3x shows how to find y-values for different x-values by calculating them and plotting the points to form a line on a graph.
Step-by-step explanation:
The student is asking to solve for y in the expression (9x + y)(y + 15). However, y cannot be directly solved from this expression without an equation or additional information. The student provided the following linear equation: y = 9 + 3x. This linear equation represents a specific line with a y-intercept (b) of 9 and a slope (m) of 3. To find values for y, you would substitute different x-values into the equation and calculate the corresponding y-values. These points can then be plotted on a graph to create a line. This procedure could be shown in Table A1 and Figure A1, as described. However, to solve the original expression for y, we would need it to be in equation form, such as (9x + y)(y + 15) = some value, and even then, we may end up with a quadratic equation requiring factoring or applying the quadratic formula to solve for y.