Question

8 si 9!va rog va dau coroana

Answer 1

8. a) x+2a-4b=15-> x+2(a-2b)=15-> x+10=15-> x=5
b)25a+x-50b=200->25(a-2b)+x=200-> 125+x=200-> x=75
c)4a-8b-x=10-> 4(a-2b)-x=10-> 20-x=10-> x=10
d)x+15+3a-6b=30-> x+3(a-2b)=15-> x+15=15-> x=0
9. a) x×y=5-> (x,y)={(1,5), (5,1)}
b)(x+1)×y=4-> (x+1,y)={(1,4),(2,2),(4,1)}-> (x,y)={(0,4),(1,2),(3,1)}
c)(x+1)(y-1)=7-> (x,y)={(0,8), (2, 6)}
d) xy+x=3-> x(y+1)=3-> (x, 1+y)={(1,3),(3,1)}-> (x,y)={(1,2),(3,0)}
e)xy-x=5-> x(y-1)=5-> (x,y)={(1,6)(5,2)}
f)2xy+6y=8-> xy+3y=4-> y=1, x=1
g)(x+2)(y-3)=12-> (x,y)={(0,9),(1,7),(2,6),(4,5),(10,4)}