Use the quadratic formula to solve
x = -1, -9
two solutions are possible
2.5-2.1=0.4
41+51=92
0.4x2+92x2=184.8 units
Since it's literally cut in half, that means the triangle's area is literally half of the rectangle's area. Therefore, if we write it as
the triangle's area (a)=(1/2)*(b) (the rectangle's area) we can multiply 2 to both sides to get 2*a=b. Since a is (2x+10), we can plug it in and use the distributive property (since we just can't add up variables and integers) to get
2*(2x+10)=4x+20=b
and not 
![x^ \frac{m}{n}= \sqrt[n]{x^m}](https://tex.z-dn.net/?f=x%5E%20%5Cfrac%7Bm%7D%7Bn%7D%3D%20%5Csqrt%5Bn%5D%7Bx%5Em%7D%20%20)
so![6 \sqrt[5]{x^3}](https://tex.z-dn.net/?f=6%20%5Csqrt%5B5%5D%7Bx%5E3%7D%20)
