Question

daca a-5d=7,atunci aflati× din relatiile:a) ×+3a-15d=29 d) ×-123+5a-25=137 c) ×-2a+10d+17=4 d) 47-×+7a-35d=2a-10+4

Answer 1

)x+3a-15d=29
  x+3(a-5d)=29
x+3*7=29
x+21=29
x=29-21
x=8

b)x-123+5a-25d=137
x+5(a-5d)=137+123
x+5*7=260
x+35=260
x=260-35
x=225
 
c)x-2a+10d+17=4
x-2(a-5d)=4+17
x-2*7=21
x-14=21
x=21+14
x=35

d)47-x+7a-35d=2a-10d+4
47-x+7(a-5d)=2(a-5d)+4
47-x+7*7=2*7+4
47-x+49=14+4
96-x=18
-x=18-96
-x=-78
x=78