Find the value of x such that the trapezoid has an area of 52

Consider the following trapezoid
The formula to find the area of this trapezoid is given by the formula
[tex]A=\frac{h(b+B)}{2}[/tex]In this case, we have h=8, b=x and B=10. So the formula for our trapezoid is given by
[tex]A=\frac{8\cdot(x+10)}{2}=4\cdot(x+10)[/tex]We are told that the area should be 52, so we end up with the following equation
[tex]4\cdot(x+10)=52[/tex]now, we should solve this equation for x. To do so, we start by dividing by 4 on both sides. So we get
[tex]x+10=\frac{52}{4}=\frac{26\cdot2}{2\cdot2}=\frac{26}{2}=13[/tex]Now, we subtract 10 on both sides, so we get
[tex]x=13-10=3[/tex]