Question

Michael and Kathryn bowled together and their combined total score for one game was 425 points. Michael’s score was 70 less than twice Kathryn’s. What were their scores

Answer 1

$x-\ Kathryn's\ points\\\\ y-\ Michael's\ points\\\\ \left \{ {{x+y=425} \atop {y+70=2x\ \ | subtract\ 70}} \right. \\\\ \left \{ {{x+y=425} \atop {y=2x-70}} \right. \\ substitution\ method\\\\ x+2x-70=425\\\\ 3x-70=425\ \ | add\ 70\\\\ 3x=495\ \ \ | divide\ by\ 3\\\\ x=165\\\\ y=2x-70=2*165-70=330-70=260\\\\ Kathryn\ scored\ 165\ points\ and\ Michael\ 260$