Choose the answer based on the most efficient method as presented in the lesson. If the first step in the solution of the equation -9 + x = 5x - 7 is "subtract x," then what should the next step be?

add 7
add 9
subtract 5x

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?

Anew test for ra is being developed. the test is administered to 750 patients with ra and 750 without ra. for the sake of the question, assume the prevalence of ra in this population is 50%. of the 750 patients with ra, 575 have a positive result. of the 750 patients without ra, 150 have a positive result. what is the positive predictive value of the new test? a575/(575+150) b. 600/(600+ 150) c. 575/(575+125) d. 600/(600+ 125)