If (y=(t+2)x-6) and (y=9x+(2t-1)) have equal slopes, what is the (y)-intercept of the second line?
Answer and explanation
Correct answer: 13
In the form \(y=mx+c\), \(m\) is the slope and \(c\) is the \(y\)-intercept. The slopes here are \(t+2\) and \(9\). Equal slopes give \(t+2=9\), so \(t=7\). The \(y\)-intercept of the second line is \(2t-1=2(7)-1=13\). Although \(11\) is the value of \(t+2\), it is not the \(y\)-intercept. Exam tip: find the parameter from the slopes first, then substitute it into the constant term.
Frequently asked questions
What is the correct answer to this question?
13
Why is this the correct answer?
In the form \(y=mx+c\), \(m\) is the slope and \(c\) is the \(y\)-intercept. The slopes here are \(t+2\) and \(9\). Equal slopes give \(t+2=9\), so \(t=7\). The \(y\)-intercept of the second line is \(2t-1=2(7)-1=13\). Although \(11\) is the value of \(t+2\), it is not the \(y\)-intercept. Exam tip: find the parameter from the slopes first, then substitute it into the constant term.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Slope and y-intercept.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
