a/3 + b/5= 7 a/4 -b/5=0 a/3 + a/4 = 7 4a/12 + 3a/12 = 7 4a/12 = 7 |*12 4a = 84 |:4 a = 21 a/3 + b/5 = 7 21/3 + b/5 = 7 b/5 = 7 - 7 b/5 = 0 b = 0 k/3 +1/4 =1 k/4+1/8 =1 k/4 + 1/8 = k/3 + 1/4 k/4 - k/3 = 1/4 - 1/8 3k/12 - 4k/12 = 1/4 - 2/4 -k/12 = -1/4 |*(-12) k = 1/4 * 12 k = 3 Tutaj nie było drugiej literki? same k? 5x - 5y =2,5 |*3 7y+ 3x =14,5 |*5 15x - 15y = 7,5 15x + 35y = 72,5 15x = 7,5 + 15y 7,5 + 15y + 35y = 72,5 15y + 35y = 72,5 - 7,5 50y = 65 |:50 y = 1,3 5x - 5y =2,5 5x = 2,5 + 5y 5x = 2,5 + 5*1,3 5x = 2,5 + 6,5 5x = 9 |:5 x = 1,8
a/3 + b/5= 7 /*15 a/4 -b/5=0 5a + 3b = 105 a/4 = b/5 /*20 5a = 105 - 3b a = 4/5 b 4b = 105 - 3b a = 4/5 b 7b = 105 a = 4/5 b b = 15 a = 12 W tym zadaniu chyba cos pomyliles k/3 +1/4 =1 /*3 k/4+1/8 =1 /*4 k + 0,75 = 3 k + 0,5 = 4 k = 2,25 k = 3,5 5x - 5y =2.5 /:5 7y+ 3x =14,5 x - y = 0,5 7y + 3x = 14,5 x = 0,5 + y 7y + 3*(0,5 +y) = 14,5 x= 0,5 + y 7y + 1,5 + 3y = 14,5 x = 0,5 + y 10y = 13 /10 x = 0,5 + y y = 1,3 x = 1,8 y = 1,3
