Topic review.

Substitution. Replace each letter with its value before calculating. For $A=lw$, $l=5$ and $w=3$ give $A=5\times 3=15$.

Expressions. Keep the order clear. Three times the whole sum of $x$ and $2$ is $3\left(x+2\right)$.

Equations. Undo operations in reverse order, do the same to both sides, then check in the original equation.

Real graphs. Read both axes and units. Use plotted values to support a trend; historical averages do not predict a particular day.

Patterns and plotting. Match the rule to the table and plot each pair in $\left(x,y\right)$ order. Whole-number stage points stay separate. For a straight-line relationship where a measurement varies continuously, join the points with a ruler.

Comparing formulas. Substitute one changed input while holding the others fixed. Record each calculation and compare the results.