Question

afla numerele necoscute
a) 25+a:(20+4×28-4)=39
b) 52×+b=142×3+25×4
c) 20+3×12+c+=148
d) d-2×(480×2-90÷10)+5=75

Answer 1

a)
 25+a:(20+4×28-4)=39
a : ( 20 +112 - 4) =39 - 25
a : 128 = 14
a = 14×128
a=1 792

b)
52×+b=142×3+25×4
52 × ? = 426 +100
52 ×?+b=526

c)
20+3×12+c=148
20 +36 +c =148
c =148 - 56
c = 92

d)
 d-2×(480×2-90÷10)+5=75
d - 2×( 960 - 9) +5 =75
d - 2 ×951 = 75 -5
d - 1902 =70
d = 70 + 1 902
d = 1 972