<span>987 - (х + 364 )= 519
</span>х + 364=987-519
х + 364=468
х=468-364
х=104
4:1 1/2+2 1/3*7 1/7=
4/1*2/3+7/3*50/7=
8/3+50/3=58/3=19 1/3
4 5/6 - 2 5/12 = заменяем неправильной дробью. Получается: 29/6 - 29/12 = 58-29/12=29/12= 2 5/12
10 4/9 - 8 5/18= 2 1/6 или 13/6
552.
a) x + 2x + 2x - 7 = 5x - 7
б) y + 4y + 4y - 10 = 9y - 10
553.
a) 5x - 7 = 68
5x = 75
x = 15
AB = 15, BC = 30, AC = 23
б) 9y - 10 = 197
9y = 207
y = 23
AB = 23, BC = 92, AC = 82