How do you solve 15 - 1 ( 12 divided by 4 + 1 )= ?

What is the smallest integer n such that n\sqrt{2} is greater than 20

Solve the given system of equations. 2y= -x+9 , 3x-6= -15

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.