Question

determinati nuparul real m pentru care ecuatia mx plus (2m minus 1)y plus 18 egal 7 plus 3m (x,y) apartine R, are ca solutie (minus 2 ; 3)

Answer 1

Răspuns:

a) ecuatia 2x+m=4x+4 are solutia -2

2×(-2)+m=4×(-2)+4

-4+m=-8+4

-4+m=-4

m=0

b)ecuatia m(x+2) +3(x-1)=mx-3 ,are solutia 0

m(0+2) +3(0-1)=m×0-3

2m -3=0-3

2m =0

m=0

c) ecuatia 2x-m(x+3) =7mx+12 are solutia 5

2×5-m(5+3) =7m×5+12

10-8m =35m+12

43m=-2

m=-2/43

d)ecuatia  -3x +4(mx-1)=6x+2-7(m+2) are solutia 3

-3×3 +4(m×3-1)=6×3+2-7(m+2)

-9+12m-4=18+2-7m-14

12m-13=6-7m

19m=19

m=1

e)ecuatia 3(m-1)(x+2) -2(2m-1)(2x+1) =7x+3mx-5 are solutia -3 3(m-1)(-3+2) -2(2m-1)[2×(-3)+1] =7×(-3)+3m×(-3)-5

-3(m-1) +10(2m-1) =-21-9m-5

-3m+3 +20m-10 =-21-9m-5

17m-7=-9m-26

26m=-19

m=-19/26

Explicație pas cu pas: