Can someone simplify these using product notation?

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =

Asystem of linear equations contains two equations with the same slope. select all of the correct statements. i a. the system may have two solutions. - b. the system may have infinitely many solutions. c. the system may have one solution. o d. the system may have no solution. submit