What are the coordinates of the image of the point (4, 2) after a dilation with a center of (0, 0) and a scale factor of 2? a. (0, 0) b. (2, 1) c. (4, 2) d. (8, 4)

Option D (8,4)

Step-by-step explanation:

we know that

The dilation centered at the origin  (0,0) is very simple. To find out the image point multiply the scale factor to the x  and  y-coordinates of the pre-image point.

so

(2*4,2*2) > (8,4)

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4