set each factor equal to 0 and solve for x ...Solve this polynomial inequality algebraically (number line)? (7x+2) (1-x)(2x-5)>0
you should get , , and
plot these three x-values on a number line in correct order.
the three plotted values of x break up the number line into four intervals ...
pick any single value in each interval, substitute it into the original inequality, and see if the result makes the original inequality true or false.
if true, then all values in that interval will make the inequality true ... the interval is part of the solution set.
if false, reject that interval as part of the solution set.