we have that
ax –y=4
if the graph of the equation would pass through the point M (3, 5)
then
for the point M (3, 5)
x=3
y=5
I substitute the values of x and y in the equation
ax –y=4---------> a*3-5=4------> a*3=4+5-------> a=9/3
a=3
the answer is
a=3