Question

Daca a-5b=7,atunci aflati xdin relatiile:
a) x+2a-15b=29
b) x-2a+10b+17=4
c) x-123+5a-25b=137
d) 47-x+7a-35b=2a-10b+4

Answer 1

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

 b) x-2a+10b+17=4
x-2(a-5b)=4-17
x-2*7=-13
x=-13+14
x=1

 c) x-123+5a-25b=137
x+5(a-5b)=137+123
x+5*7=260
x=260-35
x=225


 d) 47-x+7a-35b=2a-10b+4
-x+7a-35b-2a+10b=+4-47
-x+5a-25b=-43
x-5(a-5b)=43
x-5*7=43
x=43+35
x=78