Question

Daca a-5b=7,atunci aflati x din relatiile: a) x+3a-15b=29; b) x-123+5a-25b=137; c) x-2a+10b+17=4; d) 47-x+7a-35b=2a-10b+4 Va rog !!!!!

Answer 1

Din ecuatia a-5b=7 => a=7+5b si inlocuiesti.
a) x+3(7+5b)-15b=29 <=> x+21+15b-15b=29 <=> x+21=29 =>x=29-21=8
b) x-123+5(7+5b)-25b=137 <=> x-123+35+25b-25b=137 <=>x-123+35=137 <=> x=137+123-35 => x=225
c) x-2(7+5b)+10b+17=4 <=>x-14-10b+10b+17=4 <=> x-14+17=4 <=> x=4+14-17 => x=1
d) 47-x+7(7+5b)-35b=2(7+5b)-10b+4 <=> 47-x+49+35b-35b=14+10b-10b+4 <=> 47-x+49=14+4 <=> x=47+49-14-4 => x=78