first we represent the unknowns using variables:
let x = measure of angle 4
let 3x+4 = measure of angle 3 (from the second statement)
then we set-up the equation. since the angles form a linear pair, their sum is equal to 180 degrees. therefore,
x + 3x + 4 = 180
4x + 4 = 180
4x = 176
x = 44 degrees (measure of angle 4)
3x + 4 = 136 degrees (measure of angle 3)
