4x + 3x = 98
7x = 98
x=14
4(14)=56 (one side of the monitor) - so this is a
3(14)=42 (other side of the monitor) - so this is b
diagonal, so use hypotenuse of two sides.
a squared + b squared equals c squared.
56 squared equals 3136
42 squared equals 1764
add those together and take the square root
the diagonal equals 70