Question

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

Answer 1

5(3a+5)-3=292
15a+25=295
15a=295-25
15a=270
a=270/15
a=18

2(b-5)=30
b-5=30/2
b=15+5
b=20

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

[2(d-30)-45]*3=165
2d-60-45=165/3
2d-105=55
2d=55+105
2d=160
d=80