Question 1137254
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T + G = 348

T - G = 132

-------------------- Add the equations.


2T = 348 + 132 = 480  ======>  T = 480/2 = 240.  It is what Teddy earned.


G = 240 - 132 = 108.   It is what Gavin earned.


Teddy  cut  240/20 = 12 lawns.

Gavin  cut  108/18 =  6 lawns.


<U>CHECK</U>.   12*20 - 6*18 = 132.    ! Correct !
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Solved, checked, explained and completed.