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Algebra / Linear equations in one variable Difficulty: Hard

12x+284-s13=rx-812x+284-s13=rx-8

In the given equation, ss and rr are constants, and s>0s>0. If the equation has infinitely many solutions, what is the value of ss ?

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Explanation

The correct answer is 403403. For a linear equation in one variable to have infinitely many solutions, the coefficients of the variable must be equal on both sides of the equation and the constant terms must also be equal on both sides of the equation. The given equation can be rewritten as 43x+74-s13=rx-843x+74-s13=rx-8, or 3x+7-s13=rx-83x+7-s13=rx-8. Applying the distributive property to the right-hand side of this equation yields 3x+7-s13=rx-8r3x+7-s13=rx-8r. For this equation to have infinitely many solutions, the coefficients of xx must be equal, so it follows that 3=r3=r. Additionally, the constant terms must be equal, which means 7-s13=-8r7-s13=-8r. Substituting 33 for rr in this equation yields 7-s13=-837-s13=-83, or 7-s13=-247-s13=-24. Adding s13s13 to both sides of this equation yields 7=-24+s137=-24+s13. Adding 2424 to both sides of this equation yields 31=s1331=s13. Multiplying both sides of this equation by 1313 yields 403=s403=s. Therefore, if the equation has infinitely many solutions, the value of ss is 403403.