Question

stiind ca x+2y=3 si z= -3, calculati
a. 8-2x-4y
b.3z+2x+4y
c. 5x+10y-3z
d.xz+2yz+10
r.2xz+4yz-3z​

Answer 1

Răspuns:

a)2

b)-3

c)24

d) 1

e) -9

Explicație pas cu pas:

a) 8-2x-4y= 8-(2x+4y)=8-6=2

b)3z+2x+4y=3*(-3) + 2(x+2y)= -9+6= -3

c) 5x+10y-3z=5(x + 2y) -3*(-3)=5*3+9=24

d)xz+2yz+10=z(x+2y)+10= -3*3+10=-9+10=1

e)2xz+4yz-3z=z(2(x+2y)-3)= -3(6-3)= -3*3= -9

Answer 2

a) 8 - 2x - 4y =
8 - 2( x - 2y) =
8 - 2*3 =
8 - 6 = 2


b) 3z + 2x + 4y =
3*(-3) + 2 (x + 2y) =
-9 + 2*3 =
-9 + 6 = -3


c) 5x + 10y - 3z =
5( x + 2y) - 3*(-3) =
5*3 + 9 =
15 + 9 = 24


d) xz + 2yz + 10 =
z ( x + 2y) + 10 =
-3*3 + 10 =
-9 + 10 = 1


r) 2xz + 4yz - 3z =
2z ( x + 2y) -3* (-3) =
2*(-3)*3 + 9 =
-6*3 + 9 =
-18 + 9 = -9