OK mymathlab sucks, lol. Please help me figure this out... Write an equation of the line containing the given point and perpendicular to the given line. Express your answer in the form y=mx+b.

(4,9); 2x+y=4

the answer I got is -2/1x+21

Question

OK mymathlab sucks, lol.  Please help me figure this out...  Write an equation of the line containing the given point and perpendicular to the given line. Express your answer in the form y=mx+b.

(4,9); 2x+y=4

the answer I got is -2/1x+21

lalaly · Answer

$$y=-2x+4$$the slope of the perpindicular line is the negative reciprocal of the slope of the given line

slope of perpindicular line =$$\frac{1}{2}$$
now$$y-y_1=m(x-x_1)$$
$$y-9=\frac{1}{2} (x-4)$$

lalaly · Answer

$$y=\frac{1}{2}x+7$$

anonymous · Answer

it would be a -1/2 right? the perpendicular line

lalaly · Answer

no coz its already -2
so the negative reciprocal of -2 is 1/2

anonymous · Answer

the original was a 2x I had figured the -2 as my answer.

lalaly · Answer

it has to be in the form y=mx+b

anonymous · Answer

ok I got ya, now I see my mistake, thank you so much.

lalaly · Answer

no problem=)