Question

a) Se stie ca:x+y=23 si z=15.Calculati xz+yz
b)Se stie ca :x-y=12 si z=10.Calculati xz-yz
c)Se stie ca ab+ac=420 si b+c=14.Aflati a.
d)Se stie ca :ab-ac=135 si a=9.Aflati b- c
Cine ma poate ajuta si pe mine va rog frumos!
Urgent!!!!!!!!!!

Answer 1

a) x+y=23, z=15
xz+yz=z(x+y)=15x23=345

b) x-y=12, z=10
xz-yz=z(x-y)=10x12=120

c) ab+ac=420, b+c=14

ab+ac=420
a(b+c)=420
ax14=420
a=420:14
a=30

d) ab-ac=135, a=9

a(b-c)=135
9(b-c)=135
b-c=135:9
b-c=15

Answer 2

x+y=23,z=15deci xz+yz=z(x+y)=15*23=345b)x-y=12,z=10calc xz-yz.z(x-y)=10*12=120 c)ab+ac=420si b+c=14deci a=a(b+c)=420,a*14=420 deci a=420/14si a=30 d)ab-ac=135si a=9 aflati b-c.deci a(b-c)=135,9(b-c)=135,b-c=135/9si deci b-c=15