Question

PLEASE HELP!! Write an equation for the line that passes through the point (1, 5) and is perpendicular to the graph of x + 2y = 4. Enter your answer in the boxes. y = __ x + __
Help please I don't understand.

Answer 1

Perpendicular lines have the slopes which product is - 1:
m 1 * m 2 = - 1
First we must transform the first line to the slope-intercept form:
x + 2 y = 4
2 y = - x + 4  /:2
y = - 1/2 x + 2
Therefore: m 1 = - 1/2
( - 1/2 ) * m 2 = - 1
m 2 = ( - 1 ) : ( - 1/2 ) = ( - 1 ) * ( - 2 ) = 2
m = 2 ( this is the slope that we need for our equation )
Then we will charge it to the formula : y = m x + b ( which also passes through the point ( 1. 5 ) ):
5 = 2 * 1 + b
5 = 2 + b
b = 5 - 2
b = 3
Answer:
y = 2 x + 3