Please help, I don’t understand

What should be done to solve the equation? x+14=21 add 14 to both sides of the equation. subtract 14 from the left side of the equation. add 14 to the left side and subtract 14 from the right side of the equation. subtract 14 from both sides of the equation.

If 1 is divided by the sum of y& 4.the result is equal to 3 divided by 4, find the value of m

How do i find the missing angle measure in a polygon