Question

Determinati termenul necunoscut din egalitatile urmatoare:(3×a+5)×5-3=292, (b-5)×2=30, (c-17)×3+15=45, [2×(d-30)-45]×3=165

Answer 1

(3×a+5)×5-3=292
(3×a+5)×5=292+3
(3×a+5)×5=295
3a+5=295/5
3a+5=59
3a=59-5
3a=54
a=18

(b-5)×2=30
b-5=30/2
b-5=15
b=15-5
b=10

(c-17)×3+15=45
(c-17)×3=45-15
(c-17)×3=30
c-17=30/3
c-17=10
c=10+17
c=27

[2×(d-30)-45]×3=165
2(d-30)-45=165/3
2(d-30)-45=55
2(d-30)=55+45
2(d-30)=100
d-30=50
d=80