What is missing in the solution to the system of equations? 4x-3y=1 5x+4y=9

The mean temperature for the first 4 days in january was 7°c. the mean temperature for the first 5 days in january was 5°c. what was the temperature on the 5th day?

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line

One number is 4 less than 3 times a second number. if 3 more than two times the first number is decreased by 2 times the second number, the result is 11. use the substitution method. what is the first number?