1. Раскройте скобки: 1) (a b) + (c d)

1) (a b) + (c d) = a b + c d.
2) - (-a + b) (- c d) = a b +c +d.
3) (a + b) (c + d) = a + b c d.
4) (a + b) + (- c d) = a b c d.
5) (a b) (c + d) = - a + b c d.
6) (a b) - (c d) = a b c +d.
7)- (-a - b) + (- c d) = a + b c d.
8) (a + b) + (- c + d) = a +b c + d.
9) (a - b) + (-c d) = - a + b c d.
10) (a + b) (c + d) = a b c d.
а) 84 х + 36 = 18;
х = 18 84 36;
х = - 102;
х = 102.
б) 96 26 + y = 4;
y = - 66.