11. The line with equation $y=2 x+3$ is reflected in the $x$-axis. Which of the following is the equation of the new line?
A $y=2 x-3$
B $y=-2 x+3$
C $x=2 y+3$
D $y=\frac{1}{2} x+3$
E $y=-2 x-3$
11. E The diagram shows that the reflection of the line $y=2 x+3$ in the $x$-axis has gradient -2 and an intercept on the $y$-axis of $(0,-3)$.
Therefore, the equation of the reflected line is $y=-2 x-3$.
(Note that reflection in the $x$-axis changes $y$ to $-y$.
Hence the equation of the reflected line is $-y=2 x+3$, so $y=-2 x-3$.)