Think of $7p - 4p$ as $(7 - 4)p$. What number do you get for the coefficient of $p$?

Now think of $6q - 5q$ as $(6 - 5)q$. What number multiplies $q$ after you combine them?

After you have one term with $p$ and one term with $q$, write them together and see which answer choice matches that expression.

In an expression line, type 7p - 4p + 6q - 5q. Desmos will automatically show a simplified form of this expression next to what you typed.

Look at the simplified expression that Desmos displays and compare its terms and signs to each answer choice to see which one matches exactly.

Look at the expression $7p - 4p + 6q - 5q$.

• Terms with $p$: $7p$ and $4p$
• Terms with $q$: $6q$ and $5q$

Only like terms (same variable and power) can be combined.

Focus on $7p - 4p$.

• Combine the coefficients: $7 - 4 = 3$
• Keep the variable $p$

So $7p - 4p = 3p$.

Now focus on $6q - 5q$.

• Combine the coefficients: $6 - 5 = 1$
• Keep the variable $q$

So $6q - 5q = 1q$, which we usually just write as $q$.

Replace the original groups of terms with the simplified ones:

• $7p - 4p$ becomes $3p$
• $6q - 5q$ becomes $q$

So the whole expression is $3p + q$, which corresponds to choice D.