What exactly are you trying to say ?
X, y - the numbers
The sum of the two numbers is 50.
![x+y=50 \\ x=50-y](https://tex.z-dn.net/?f=x%2By%3D50%20%5C%5C%0Ax%3D50-y)
The first number is 43 less than twice the second number.
![x=2y-43 \\ \\ 50-y=2y-43 \\ -y-2y=-43-50 \\ -3y=-93 \\ y=31 \\ \\ x=50-y=50-31=19](https://tex.z-dn.net/?f=x%3D2y-43%20%5C%5C%20%5C%5C%0A50-y%3D2y-43%20%5C%5C%0A-y-2y%3D-43-50%20%5C%5C%0A-3y%3D-93%20%5C%5C%0Ay%3D31%20%5C%5C%20%5C%5C%0Ax%3D50-y%3D50-31%3D19)
The numbers are 19 and 31.
The formula for lateral surface of a cylinder is:
SA = 2 *PI * r *h
Replace the letters with the given values:
400 = 2 * PI * r *40
Multiply the right side:
400 = r * 251.2
Divide both sides by 251.2:
r = 400 / 251.2
r = 1.59
The radius is 1.59 inches.