Вправи 1201 - 1300 » 1277 (17-20)

17) –3,4 (х + 93/11) = –68; х + 93/11 = 20; х = 1911/11 – 93/11; х = 108/11. 18) х/3 + х/4 = –21; 7х/12 = –21; х = –21 : 7 ∙ 12; х = –36. 19) 2m/3 – 4m/5 = 3; – 2m/15 = 3; m = 3 ∙ 15 : (–2); m = –221/2. 20) 4a/9 – 1 = 5a/12; 16a/36 – 15a/36 = 1; a/36 = 1; a = 36.