Question a-prop

1.4 Systems of Two Linear Equations - Substitution method
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A proposal for a new library was included on an election ballot. A radio show stated that 3 times as many people voted in favor of the proposal as people who voted against it. A social media post reported that 15,000 more people voted in favor of the proposal than voted against it. Based on these data, how many people voted against the proposal?

A.

7,500

B.

15,000

C.

22,500

D.

45,000

A proposal for a new library was included on an election ballot. A radio show stated

Hard-difficulty · SAT Math · Systems of Two Linear Equations — Substitution method. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

Choice A is correct. It's given that a radio show stated that 3 times as many people voted in favor of the proposal as people who voted against it. Let x represent the number of people who voted against the proposal. It follows that 3 x is the number of people who voted in favor of the proposal and 3x-x, or 2 x , is how many more people voted in favor of the proposal than voted against it. It's also given that a social media post reported that 15,000 more people voted in favor of the proposal than voted against it. Thus, 2x=15,000. Since 2x=15,000, the value of x must be half of 15,000 , or 7,500 . Therefore, 7,500 people voted against the proposal.

Choice B is incorrect. This is how many more people voted in favor of the proposal than voted against it, not the number of people who voted against the proposal.

Choice C is incorrect. This is the number of people who voted in favor of the proposal, not the number of people who voted against the proposal.

Choice D is incorrect and may result from conceptual or calculation errors.