Help it's due rn will mark brainliest. it is 8th math

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28

One file clerk can file 10 folders per minute. a second file clerk can file 11 folders per minute. how many minutes would the two clerks together take to file 672 folders?

Geometry - finding area of regular polygons and sectors (check my math, i can’t find the error)