Question 88·Easy·Equivalent Expressions
Which of the following is equivalent to ?
For expression-equivalence questions like this, work algebraically and systematically: first apply the distributive property to remove parentheses, then combine like terms (especially constants) with careful attention to signs. Avoid mental shortcuts that skip the distribution step, since they often cause sign or constant-term errors. If unsure, you can also plug in a simple value for the variable into both the original expression and each choice to see which one always produces the same result, but distribution and simplification are usually fastest on the SAT.
Hints
Focus on the parentheses
Look at . What should you do first with the and the expression in parentheses?
Use the distributive property
Multiply 4 by each term inside the parentheses: once by and once by .
Combine constant terms carefully
After you distribute, you will have a term with and some constant numbers. Combine the constant numbers, paying close attention to their signs (positive/negative).
Desmos Guide
Define the original expression in Desmos
In Desmos, type f(y) = 4(2y - 3) + 5. This will let you quickly evaluate the original expression for different values of .
Test a specific value of y
Pick a simple value, such as , and type f(1) to see the numeric result of the original expression. Note that value.
Compare each answer choice
For each option, create a function in Desmos, for example A(y) = 8y - 7, B(y) = 8y + 7, etc. Then evaluate each at (for example, A(1), B(1), etc.) and see which one matches the value of f(1).
Confirm with a second value
To be sure, test another value like or and compare f(2) or f(-1) with the values from each answer choice. The expression that matches the original for both values is the equivalent one.
Step-by-step Explanation
Apply the distributive property
Start with the expression .
Use the distributive property: multiply 4 by each term inside the parentheses:
So becomes .
Simplify the distributed terms
Now simplify each product:
So becomes .
The whole expression is now .
Combine like constant terms
Combine the constant terms and :
So the constant terms combine to .
Match with the answer choices
From the simplification, is equivalent to .
So the correct choice is .