\(a,33+x=71-26\\ 33+x=45\\ x=45-33=12\\ b,x+73=76+26\\ x+73=102\\ x=102-73=29\\ c,x+9=45-6\\ x+9=39\\ x=39-9=30\\ d,73-x=89-20\\ 73-x=69\\ x=73-69=4\)
a) ( 33 + x ) = 71 - 26
33 + x = 45
x = 45 - 33
x = 12
b) x + 73 = 76 + 26
x + 73 = 102
x = 102 - 73
x = 29
c) x + 9 = 45 - 6
x + 9 = 39
x = 39 - 9
x = 30
d) 73 - x = 89 - 20
73 - x = 69
x = 73 - 69
x = 4
e) x + 7 = 13 + 25
x + 7 = 38
x = 38 - 7
x = 31
f) x + 4 = 198 - 120
x + 4 = 78
x = 78 - 4
x = 74
g) 2(x - 51) = 2.8 + 20
2(x - 51) = 16 + 20
2(x - 51) = 36
x - 51 = 36 : 2
x - 51 = 18
x = 18 + 51
x = 69
h) x - 19 = 450 : 50
x - 19 = 9
x = 9 + 19
x = 28
i) 4(x - 3) = 49 - 1
4(x - 3) = 48
x - 3 = 48 : 4
x - 3 = 12
x = 12 + 3
x = 15
