A triangle with vertices (2, 9), (-5, 1), and (1, -4) is dilated by a scale factor of 4. Which matrix expression represents the transformation?
Answer choices:
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Question

SmokeyBrown · Answer

I'm pretty sure that the first answer choice is correct. I think coordinates in matrices are ordered top-to-bottom, so that's the one that matches the coordinates of the triangle.

Study2Learn · Answer

Could you please be little more precise?

Study2Learn · Answer

I'm not really sure if you truly know the answer because of  explanation, sorry, I just want to understand.

SmokeyBrown · Answer

Yeah no problem.
So, when you convert a set of coordinates into a matrix, you place the coordinate values in the matrix column by column. So, the first column represents one coordinate point, the second column represents another coordinate point, and so on.
The only answer choice that matches this format is the first one. Notice how the first column corresponds to the point (2,9), the second column corresponds to the point (-5,1), and the third column corresponds to the point (1,-4), just like the vertices of the triangle?
Of course, the entire matrix is multiplied by 4, since the shape is being dilated, or increased by a factor of 4, but that is true of all the answer choices.

Study2Learn · Answer

Thank you so much!

SmokeyBrown · Answer

No problem, I'm glad I could help!