[tex]A=44\ m^2\\\\l,\ l+3-the\ lengths\ of\ legs[/tex]
The formula of an area of a right trinagle:
[tex]A=\dfrac{l_1l_2}{2}[/tex]
Substitute:
[tex]\dfrac{l(l+3)}{2}=44[/tex] multiply both sides by 2
[tex]l(l+3)=88[/tex] use distributive property
[tex]l^2+3l=88[/tex] subtract 88 from both sides
[tex]l^2+3l-88=0[/tex]
[tex]l^2+11l-8l-88=0[/tex]
[tex]l(l+11)-8(l+11)=0[/tex]
[tex](l+11)(l-8)=0\iff l+11=0\ \vee\ l-8=0\\\\l=-11<0\ \vee\ l=8[/tex]
[tex]l=8\\l+3=8+3=11[/tex]