In the line (y=-7x+20), what change occurs in (y) when (x) increases by (1)?
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Answer and explanation
Correct answer: Decreases by 7
In the form y = mx + c, the coefficient of x, m, is the slope. Here the slope is -7, so an increase of 1 in x produces a change of -7 in y; therefore, y decreases by 7. The number 20 is the y-intercept, not the change in y. Exam tip: for a 1-unit increase in x, the change in y equals the slope.
Frequently asked questions
What is the correct answer to this question?
Decreases by 7
Why is this the correct answer?
In the form y = mx + c, the coefficient of x, m, is the slope. Here the slope is -7, so an increase of 1 in x produces a change of -7 in y; therefore, y decreases by 7. The number 20 is the y-intercept, not the change in y. Exam tip: for a 1-unit increase in x, the change in y equals the slope.
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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