Answer:
13 inches
Explanation:
First you have to solve for x. Here is what we know.
The perimeter is the sum of all of the sides of the triangle.
The perimeter is equal to 30 inches.
So if we add up all of the sides and set that equal to 30 then you can solve for x.
![30= (2x+3) + (x) + (4x-8)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/4loby8ymqa7ui7seavxx1mmcq203gfb1gf.png)
Then combine the like terms.
![30=2x+x+4x +3-8](https://img.qammunity.org/2021/formulas/mathematics/middle-school/wvzuxfvsgeb2vn1kxrafborc5mydwezhr1.png)
Then solve for x.
![30+5=7x\\(35)/(7) =x\\x=5](https://img.qammunity.org/2021/formulas/mathematics/middle-school/pnpdgndw1dvwmp3y6as6594ki4l68lcl6s.png)
Now that you know x you can plug it into the equation for the longest side.
![2x+3\\2(5)+3\\10+3\\13 inches](https://img.qammunity.org/2021/formulas/mathematics/middle-school/z4rlabj3bhjp0msuyjsq5x2qziw0ve0se4.png)