Question

x-y=20 si ax-ay=120 calculati a
ax+ay=875 si a=7 calculati x+y
x+y+z=256 si t=40 calculati xt+yt+zt
x+y=856 si a=8 calculati 2x+2y-5a
x-y=12 si t=7 calculati tx-ty+t la puterea a 2

Answer 1

ax-ay=a(x-y)
a(x-y)=120
a*20=120
a=120:20
a=6

a(x+y)=875
7*(x+y)=875
x+y=875:7
x+y=125

t*(x+y+z)=40*256=10240

2*(x+y)-5a=2*856-5*8=1712-40=1672

t*(x-y+1)=7*(12+1)=7*13=91