a) 4.7 - (2a + 3.7) = 4.7 - 2a - 3.7= 1 - 2a
б) (4.5 - m) - 1.5 = 4.5 - m - 1.5 = 3 - m
в) (7.8 - x) - (3.8 + x) = 7.8 - x - 3.8 - x = 4 - 2x
г) 2x - (x - y) = 2x - x + y = x + y
д) - 12 - (x - a - 12) = -12 - x + a + 12 = -x + a
е) -4 + (4 + 7) = -4 + 4 + 7= 7
a) 4.7 - (2a + 3.7) = 4.7 - 2a - 3.7= 1 - 2a
б) (4.5 - m) - 1.5 = 4.5 - m - 1.5 = 3 - m
в) (7.8 - x) - (3.8 + x) = 7.8 - x - 3.8 - x = 4 - 2x
г) 2x - (x - y) = 2x - x + y = x + y
д) - 12 - (x - a - 12) = -12 - x + a + 12 = -x + a
е) -4 + (4 + 7) = -4 + 4 + 7= 7