Rani claims y = 5 satisfies 12 − 3y = 27, but substituting gives 12 − 15 = −3. Which value of y actually satisfies it?

Question

Accepted Answer

y = -5. Transpose the 12: −3y = 27 − 12 = 15. Divide both sides by −3: y = −5. Check: 12 − 3(−5) = 12 + 15 = 27 ✓. Answers 13 and −13 come from writing 3y = 27 + 12 = 39, adding where the sign should flip; 15 stops before dividing by −3. Since 27 is larger than 12, the term −3y must be positive, so y has to be negative.

Rani claims $y = 5$ satisfies $12 - 3 y = 27$ , but substituting gives 12 − 15 = −3. Which value of $y$ actually satisfies it?

Step-by-Step Solution

Key idea: The balance principle

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More Class 7 Simple Equations practice

Rani claims y=5 satisfies 12−3y=27, but substituting gives 12 − 15 = −3. Which value of y actually satisfies it?

Step-by-Step Solution

Key idea: The balance principle

Master this chapter in 30 minutes a day.

More Class 7 Simple Equations practice

Rani claims $y = 5$ satisfies $12 - 3 y = 27$ , but substituting gives 12 − 15 = −3. Which value of $y$ actually satisfies it?