The equation for h(x) is h(x) = -2x. Whatever the input is, we multiply it by -2 to get the output. Eg: x = -1 leads to y = 2 y = -2x y = -2*(-1) ... plug in x = -1 y = 2 ... and we get the proper y value from the table
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Once we get to h(x) = -2x, we replace h(x) with y, swap x and y, then solve for y h(x) = -2x y = -2x x = -2y -2y = x y = -x/2 y = (-1/2)x which is why the inverse function is choice D
