Question

Find an equation of a line through (2, 1) and perpendicular to −2x + 4y = 8

Answer 1

Hello:
the equation is : y = ax+b
the slope is a : a×(1/2) = -1......( perpendicular to a line with a slope of   1/2)            because :    -2x+4y =8...y=(1/2)x+2    )     

a = -2       y=(-2x+b
the line that passes through (2,1) :1 = -2(2)+b
b =5
 the equation is :  y  = -2x+5