Question

Va rog...urgent...ajutor...

Answer 1

13.

x-apart. cu 2 camere

y-apart. cu 3 camere

x+y=51 =>x=51-y

2x+3y=132

2(51-y)+3y=132

102-2y+3y=132

y=30 =>x=21

14.

a+b=231

75% înseamnă 75/100 sau 3/4

a=3b/4

3b/4 + b = 231

3b+4b=231•4

7b=231•4

b=(231•4)/7=33•4

b=132 =>a=(3•132)/4=3•33

a=99

Answer 2

Salut,

ex 13:

x+y=51

x=51-y

2x+3y=132

2(51-y)+3y=132

102-2y+3y=132

y=30

x=51-30

x=21

ex 14:

a+b=231

a=75/100b=3/4b

3/4b+b=231

3b+4b=924

70=924

b=924:7

b=132

a=3/4×132

a=99