Let the marks of Devi be x and Ali be y.
So, the equations:
2y = x <em>and</em> y + 16 = x
So,
2y = y + 16. [ because we know equals are equal to equals]
=> 2y - y = 16
=> y = 16
Check
Ali's marks are half of Devi's marks.
Devi's marks are 16 more than alis.
So, Devi's marks will be 16×2 = 32 and 32 is 16 greater than 16 (16+16=32).
12.9 = x + 7.1
subtract 7.1 from both sides to isolate the variable, x.
5.8 = x
5.8 is your answer.
Answer:
Slope of a horizontal line. When two points have the same y-value, it means they lie on a horizontal line. The slope of such a line is 0, and you will also find this by using the slope formula.
They are inverse functions though to be completely thorough your teacher should have also put g(f(x)) = x as well. Though I can see what your teacher is aiming for at least.
The idea is that whatever the output of g(x) is, it's plugged into f(x) and the initial input is the result. So g(x) takes a step forward and f(x) takes a step back undoing everything g(x) did. Which is exactly what an inverse operation does.
