Answer:
[tex]a=\frac{y-d}{x}[/tex]Explanation:
To solve for a in the the equation
[tex]y=ax+d[/tex]we first subtract d from both sides to get
[tex]y-d=ax+d-d[/tex][tex]y-d=ax[/tex]Finally,
[tex](y-d)\div x=\frac{ax}{x}[/tex][tex]\frac{y-d}{x}=a[/tex]A bit of rearranging gives
[tex]a=\frac{y-d}{x}[/tex]