Four more than the product of a number and 7 is equal to 3translate sentence into equation

3x + 4y = 5 x- 3y = -7 solve by substitution

Jeremy wants to determine the number of solutions for the equation below without actually solving the equation. which method should jeremy use?

The first week samantha learned to read braille, she could read 10 words per minute. in the second week she increased her speed by 20%. in the third week she increased her speed again by another 25%. how many words could she read per minute by the third week? hurry and tell me!