a) 84-8x4+25= 84-40+25=44+25=69
b) 25+40: 4x6= 25+10x6= 25+60= 85
c) 8x8: 8+8= 64: 8+8 = 8+8= 16
d) 66: (4x4-4: 4-4x4: 4) = 66: (16-4:4-4x4: 4) =
= 66: (16-1-4x4:4) = 66: (16-1-16:4) =
= 66: (16-1-4) = 66: (15-4) = 66: 11 = 6
e) 70: (4x4-4: 4-4: 4) = 70: (16-1-4:4) =
= 70: (16-1-1) = 70: 14 = 5
f) 6+(6x6: 6-6)x6= 6+(36: 6-6) = 6+(6-6)=6+0=6
g) (15+60: 10) - 3x7= (15+6) - 3x7= 21-21 = 0
h) (40+20x3) - 120:10= (40+60) - 12=100-12=88
