The line (y=mx+7) passes through ( (-2,1) ). What is its slope?
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Answer and explanation
Correct answer: 3
Substitute the point (-2,1) into y=mx+7: 1=m(-2)+7. Thus, 1=-2m+7, so -2m=-6 and m=3. Therefore, the slope is 3. If m were -3, the y-coordinate would be 13, not 1. Exam tip: substitute both coordinates carefully, especially when the x-coordinate is negative.
Frequently asked questions
What is the correct answer to this question?
3
Why is this the correct answer?
Substitute the point (-2,1) into y=mx+7: 1=m(-2)+7. Thus, 1=-2m+7, so -2m=-6 and m=3. Therefore, the slope is 3. If m were -3, the y-coordinate would be 13, not 1. Exam tip: substitute both coordinates carefully, especially when the x-coordinate is negative.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Slope and y-intercept.
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