Answer:
![p = \dfrac{q - 4r}{3}](https://tex.z-dn.net/?f=%20p%20%3D%20%5Cdfrac%7Bq%20-%204r%7D%7B3%7D%20)
Step-by-step explanation:
3p + 4r = q
3p = q - 4r
![p = \dfrac{q - 4r}{3}](https://tex.z-dn.net/?f=%20p%20%3D%20%5Cdfrac%7Bq%20-%204r%7D%7B3%7D%20)
The equation of the tangent line can be found using slope formula and fact that slope = dy/dx.
![\frac{dy}{dx} = \frac{y - y_0}{x - x_0}](https://tex.z-dn.net/?f=%5Cfrac%7Bdy%7D%7Bdx%7D%20%3D%20%5Cfrac%7By%20-%20y_0%7D%7Bx%20-%20x_0%7D)
where (x0,y0) is point A ---> (0,-1)
Then rearrange equation into slope-intercept form:
![y = \frac{dy}{dx}(x - 0) -1](https://tex.z-dn.net/?f=y%20%3D%20%5Cfrac%7Bdy%7D%7Bdx%7D%28x%20-%200%29%20-1)
Finally sub in x=0 into dy/dx to get slope at the point (0,-1)
I’m pretty sure it’s d but i’m not 100%