Answer
$a.\quad -12 $ and $-3.$
$b.\quad -5 $ and $4.$
$c.\quad -8 $ and $1.$
$d.\quad -1 $ and $8.$
Work Step by Step
$(-8,0)$ and $(1,0)$ are points on the graph of y=f(x).
$a.$
The graph of f(x) is translated to the left by $4$ units, so the new intercept points are
$(-8-4,0)$ and $(1-4,0)$
x-intercepts: $-12 $ and $-3.$
$b.$
The graph of f(x) is translated to the right by $3$ units, so the new intercept points are
$(-8+3,0)$ and $(1+3,0)$
x-intercepts: $-5 $ and $4.$
$c.$
The graph of f(x) is vertically stretched, so the new intercept points are
$(-8,0\cdot 2)$ and $(1,0\cdot 2)$
x-intercepts: $-8 $ and $1.$
$d.$
The graph of f(x) is reflected about the y-axis, so the new intercept points are
$(-(-8),0)$ and $(-1,0)$
x-intercepts: $-1 $ and $8.$