7.
7.
a)397+42 x m = 859
42 x m = 859 - 397
42 x m = 462
m = 462 : 42
m =11
b)
974-124 : n = 943
124 : n = 974 - 943
124 : n = 31
n = 124 : 31
n = 4
c)
40 x p - 500 = 300
4 x p = 300 + 500
4 x p = 800
p = 800 : 4
p = 200
8. 360-(2a+64)=278
2a+64=360-278
2a+64=82
2a=82-64
2a=18
a=9