1. Раскройте скобки: 1) (a – b) + (c – d) 2)- (-a + b) – (- c – d) 3) (a + b) – (c + d) 4) –(a + b) + (- c – d) 5) –

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.