If (y=170-10x), what is the difference between (y) at (x=4) and (y) at (x=11)?
Answer and explanation
Correct answer: 70
Putting x=4 gives y=170-10(4)=130. Putting x=11 gives y=170-10(11)=60. Therefore, the difference between the two y-values is 130-60=70. Note that 60 is the value of y at x=11, not the difference. Exam tip: For a linear expression, substitute both x-values first and then subtract the resulting y-values.
Frequently asked questions
What is the correct answer to this question?
70
Why is this the correct answer?
Putting x=4 gives y=170-10(4)=130. Putting x=11 gives y=170-10(11)=60. Therefore, the difference between the two y-values is 130-60=70. Note that 60 is the value of y at x=11, not the difference. Exam tip: For a linear expression, substitute both x-values first and then subtract the resulting y-values.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear growth and decay.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
