Question

I’m not good with quadratic equations at all

Answer 1

`A=(1)/(2)\cdot b\cdot h\\\\\\276=(1)/(2)\cdot(3x+10)\cdot x\qquad|\cdot2\\\\\\552=(3x+10)\cdot x\\\\552=3x^2+10x\\\\3x^2+10x-552=0\\\\\\a=3\qquad b=10\qquad c=-552\\\\\Delta=b^2-4ac=10^2-4\cdot3\cdot(-552)=100+6624=6724\\\\√(\Delta)=√(6724)=82\\\\\\ x_1=(-b-√(\Delta))/(2a)=(-10-82)/(6)=-(92)/(6)\ \textless \ 0\\\\\\ x_2=(-b+√(\Delta))/(2a)=(-10+82)/(6)=(72)/(6)=\boxed{12}`

So the height h = x = 12