А) 2,16а – 0,7а + 1,04а = 11,77.
2,5a = 11,77.
a = 4,708.
Б) (2,3х + 0,9):0,04 – 19,176 = 9,074.
(2,3x + 0,9):0,04 = 9,074 + 19, 176.
(2,3x + 0,9):0,04 = 28,25.
2,3x + 0,9 = 28,25 * 0,04.
2,3x = 1,13 - 0,9.
2,3x = 0,23.
x = 0,1.
В) 4,8d + 5,91 + 13,2d = 150.
18d = 150 - 5,91.
18d = 144,09.
d = 144,09 : 18.
d = 8,005.
Г) 10,72 + 0,324 : (5,5 – t : 78) = 10,8.
10,72 + 0,324:(5,5 - t:(429-x:78)) = 10,8.
10,72 + 0,324 * 78:(429 - x) = 10,8.
10,72 + (25,72:429-x) = 10,78.
(-10,72x + 4624,152):429 - x = 10,8.
-10,72x + 4624,152 = -10,8x + 4633,2.
0,08x = 9,048.
x = 9,048:0,08.
x = 113,1.