 
 <translate> Let x be the number of years Tom has been teaching. Devin has been teaching for (1 / 2)x - 5 years. 70 = x + ((1 / 2)x - 5). 70 = (3 / 2)x - 5. 75 = (3 / 2)x. x = 50. Tom has been teaching for 50 years. Final answer: 50. <hau> Bari x ya zama adadin shekarun da Tom ya koyar. Devin ya kasance yana koyarwa na (1 / 2) x - 5 shekaru. 70 = x + ((1 / 2) x - 5). 70 = (3 / 2) x - 5. 75 = (3 / 2) x. x = 50. Tom ya yi shekara 50 yana koyarwa. Amsar ƙarshe: 50. 