Question

Suppose that a, b, c, d are positive real numbers such that a/b < c/d . What can you say about the fraction (a+c)/(b+d) ? Is it always, sometimes, or never between the fractions a/b and c/d ? Provide evidence of your claim. (If always or never, give an algebraic proof, otherwise, give two quadruples values of a, b, c, d in which one quadruple has (a+c)/(b+d) between a/b and c/d and the other does not.)

Answer 1

Answer: (a−c)(b−c)>0

Step-by-step explanation:

ab>1 and ac<01. a>0 if c<0 and also b>02. a<0 if c>0 and also b<0

how i did it:

At the vert first, write the inequality as an equation.

Solve the provided equation for one or more values.

Now, display all the values obtained in the number line.

Use open circles to show the excluded values on the number line.

Find the interim.

At the moment, take any random value from the interval and substitute it in the inequality equation to check whether the values reassure the inequality equation.

Intervals that reassure the inequality equation are the solutions of the given inequality equation.