If you are unsure how to factor, distribute the 4 in the first term to rewrite the expression without parentheses, then simplify by combining like terms.

Once you simplify to a form like $ax + b$, check if there is a common factor you can pull out so that the expression is written as a number times a binomial, similar to the answer choices.

In Desmos, type the original expression as y1 = 4(2x+5)-(2x+5).

On new lines, type:

• y2 = 3(2x+5)
• y3 = 6(x+5)
• y4 = 2(4x+5)
• y5 = 4(2x-5)-(2x-5)

Look at the graphs of all the functions. The correct choice will be the one whose graph lies exactly on top of the graph of $y1$ for all $x$, meaning the two expressions are equivalent.

You can also tap on the graph or use a table to compare $y$-values for several $x$-values (for example, $x=0$, $x=1$, $x=2$). The equivalent expression will always give the same $y$-values as the original expression.

Start with the expression:

Distribute the 4 in the first term:

So the whole expression becomes:

Now subtract the binomial $(2x+5)$:

Combine like terms:

• Combine $8x$ and $-2x$ to get $6x$.
• Combine $20$ and $-5$ to get $15$.

So the expression simplifies to:

Factor $6x+15$ by taking out the greatest common factor, which is 3:

This factored form matches choice A, so the equivalent expression is $3(2x+5)$.