A student's practice questions increase as (Q(w)=20+10w). How many questions will there be at (w=4)?
Answer and explanation
Correct answer: 60
Substitute \(w=4\) into the expression: \(Q(4)=20+10\times4=20+40=60\). Therefore, the number of practice questions is 60. The value 40 represents only \(10\times4\); the initial 20 questions must also be added. Exam tip: When evaluating a linear expression, substitute the variable value, multiply first, and then add or subtract.
Frequently asked questions
What is the correct answer to this question?
60
Why is this the correct answer?
Substitute \(w=4\) into the expression: \(Q(4)=20+10\times4=20+40=60\). Therefore, the number of practice questions is 60. The value 40 represents only \(10\times4\); the initial 20 questions must also be added. Exam tip: When evaluating a linear expression, substitute the variable value, multiply first, and then add or subtract.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear growth and decay.
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