If a ship's path is mapped on a coordinate grid, it follows a straight-line path of slope 4 and passes through point (1, 2).

part a: write the equation of the ship’s path in slope-intercept form.

part b: a second ship follows a straight line, with the equation x + 4y − 20 = 0. are these two ships sailing perpendicular to each other? justify your answer.

Ship 1 : this has a slope of 4

ship 2 : 
x + 4y - 20 = 0
4y = -x + 20 
y = -1/4x + 5...slope here is -1/4

so ship 1 has a slope of 4, and ship 2 has a slope of -1/4. These ships are traveling perpendicular to each other because perpendicular lines have negative reciprocal slopes. To find the negative reciprocal of a number, flip the number and change the sign.

so take 4 or 4/1flip it, making it 1/4change the sign, making it -1/4. Hence,  ur lines have negative reciprocal slopes and are therefore, perpendicular.