When 8 is subtracted from the square of a number , the result is 7 times the number find the positive solution

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race

Find the value of x that will make l ll m

9/10 divide by -3/15 as a mixed number