Algebra URGENT
posted by Ann on .
Write an equation of a line perpendicular to y=2x+3 and passes through (3,4).

Slope of the given line is 2 , therefore the slope of the perpendicular line is (1/2)
Use your point slope equation y y =m(x  x)
Y  4 = (1/2)(x  3)
2(y  4) = 1(x  3). You are looking a proportion and cross multiplying
2y  8 = 1x + 3
2y. =. 1x + 11
y. = (1/2)x + (11/2) 
perpendicular to y = 2x + 3 implies the new equation must be
y = (1/2)x + b
sub in the point (3,4)
4 = (1/2)(3) + b
b = 4 + 3/2 = 11/2
y = (1/2)x + 11/2