Answer: a) k=8
b) The area of the addition =
![30\text{ square feet}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/vu99laqr7n3z510kna5e91vasqc7wsrosd.png)
The area of the entire patio after addition
![=80\ \text{square feet}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/a9p72i7kx7xaqlpn7xht5254vn7s4t41g2.png)
Explanation:
Given: The area of the patio before addition = 50 square feet
The area of the addition portion is given by
![k^2-3k-10](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tahz6z53juhhs9joxwd9g458mqritqyqln.png)
We can see that dimension of the total portion is
![k*(k+2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jlub65qcbu8auzdwgyk8scvqmnzmebd4wj.png)
therefore, the area of the patio with the addition portion =
![k*(k+2)=k^2+2k](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fle9julg8781beczmgiyu83epstrcccope.png)
According to the question we have,
![k^2-3k-10+50=k^2+2k\\\Rightarrow-3k+40=2k\\\Rightarrow\ 5k=40\\\Rightarrow\ k=8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/8u0mbb5b3y3p6tghrepv03yflxgwumwwsq.png)
Therefore, The area of the addition =
![8^2-3(8)-10=64-24-10=30\text{ square feet}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ec6lb701pz5l9iyhwtv8wtkqc4gmst79u1.png)
The area of the entire patio after addition =
![30+50=80\ \text{square feet}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ep3d382ap8tbbh5fbklcwzj5enngd2nx28.png)