Only the ‘č’ and ‘e’ plsd

Nine more than four times a number is the same as one less than twice the number. find the number?

How do you solving the solution of each system using elimination?

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.