13-14:X=18-7

X+5×(33+128)=895

X-53 ×(49-3×12)=996


Răspuns :

a)13-14:x=18-7

13-14:x=11

14:x=13-11

14:x=2

x=14:2

x=7

b) X+5×(33+128)=895

X+5x161=895

X+805=895

X=90

c) X-53 ×(49-3×12)=996

X-53x(49-36)=996

X-53x13=996

X-689=996

x=1685


13-14:x=18-7,  -14:x=11-13=-2, x=14/2=7, x≠0

x+5*(33+128)=895,  x+5*161=895, x+805=895, x=895-805=90

x-53*(49-3*2)=996, x-53*(49-6)=996,  x-53*43=996, x-2279=996, x=996+2279=3275