Question

methods.
point b has coordinate b(1, -1).
what is the coordinate of b under a scale factor of 3?
○ (1, -1)
○ (3, -3)
○ (-2, 2)
○ (-6, 6)

Explanation:

Step1: Recall scaling rule

To scale a point \((x, y)\) by a scale factor \(k\), we multiply each coordinate by \(k\), so the new point is \((kx, ky)\).

Step2: Apply to point B

Point \(B\) is \((1, -1)\) and scale factor \(k = 3\). Multiply \(x\)-coordinate: \(1\times3 = 3\), multiply \(y\)-coordinate: \(-1\times3=-3\). So \(B'\) is \((3, -3)\).

Answer:

B. (3, -3)