If h=4, then 5(4)+7= 27. Using PEMDAS, do multiplication first, so 20, then add the 7.
Just subtract it like normal numbers like
17-15 = 2 now just add y 17y-15y = 2y
To find the percent of the birdhouses occupied, divide the number of occupied birdhouses by how many birdhouses there are in total:
Convert this decimal into a percentage by multiplying by 100:
5.26% of the birdhouses are occupied.