If (y=5x+b) and (y=-3x+6) cut the (y)-axis at the same point, what is (b)?
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Answer and explanation
Correct answer: 6
To find a line’s y-intercept, put x=0. For the first line, y=b, while for the second line, y=6. Since both lines meet the y-axis at the same point, their y-intercepts must be equal. Hence, b=6. The number 5 is the slope of the first line, not its y-intercept. Exam tip: always set x=0 to find the y-intercept.
Frequently asked questions
What is the correct answer to this question?
6
Why is this the correct answer?
To find a line’s y-intercept, put x=0. For the first line, y=b, while for the second line, y=6. Since both lines meet the y-axis at the same point, their y-intercepts must be equal. Hence, b=6. The number 5 is the slope of the first line, not its y-intercept. Exam tip: always set x=0 to find the y-intercept.
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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