Let x be the time it takes in hours for B to clear the land......then....the amount of work that B can do in one hr = 1/x
Let x + 2 be the time in hours for A to clear the land..and the amount of work done in one hour by A is 1/(x +2)
(Amt done in one hour by each) * 22 hours = 1 whole job done.....or, mathematically......
[1/x + 1/(x+2)] *22 = 1 simplify by getting a common denominator on the left
[(x + 2 + x)] *22 / [(x(x + 2)] = 1 multiply both sides by the reciprocal of .... 22 / [(x(x + 2)]
2x + 2 = [x(x + 2)] / 22 multiply both sides by 22....expand the right side
44x + 44 = x^2 + 2x simplify some more
x^2 - 42x - 44 = 0 and using the onsite calculator we have
$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{42}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{44}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{21}}{\mathtt{\,-\,}}{\sqrt{{\mathtt{485}}}}\\
{\mathtt{x}} = {\sqrt{{\mathtt{485}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{21}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{1.022\: \!715\: \!545\: \!545\: \!240\: \!5}}\\
{\mathtt{x}} = {\mathtt{43.022\: \!715\: \!545\: \!545\: \!240\: \!5}}\\
\end{array} \right\}$$
So...it would take "B" about 43 hours to clear the land working alone......[rounded to the nearest tenth]
Let x be the time it takes in hours for B to clear the land......then....the amount of work that B can do in one hr = 1/x
Let x + 2 be the time in hours for A to clear the land..and the amount of work done in one hour by A is 1/(x +2)
(Amt done in one hour by each) * 22 hours = 1 whole job done.....or, mathematically......
[1/x + 1/(x+2)] *22 = 1 simplify by getting a common denominator on the left
[(x + 2 + x)] *22 / [(x(x + 2)] = 1 multiply both sides by the reciprocal of .... 22 / [(x(x + 2)]
2x + 2 = [x(x + 2)] / 22 multiply both sides by 22....expand the right side
44x + 44 = x^2 + 2x simplify some more
x^2 - 42x - 44 = 0 and using the onsite calculator we have
$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{42}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{44}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{21}}{\mathtt{\,-\,}}{\sqrt{{\mathtt{485}}}}\\
{\mathtt{x}} = {\sqrt{{\mathtt{485}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{21}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{1.022\: \!715\: \!545\: \!545\: \!240\: \!5}}\\
{\mathtt{x}} = {\mathtt{43.022\: \!715\: \!545\: \!545\: \!240\: \!5}}\\
\end{array} \right\}$$
So...it would take "B" about 43 hours to clear the land working alone......[rounded to the nearest tenth]