Question

20y + 10y = 10
x + y = 10

Answer 1

{20y + 10y = 10
{x + y = 10=> x= 10-y

20y + 10y = 10
20y+10.(10-y)=10
20y+100-10y=10
10y= 10-100
10y= -90
y= -90/10
y= -9


x= 10-y
x= 10-(-9)
x= 10+9
x= 19

PROVA REAL

X= 10-Y
19= 10-(-9)
19= 10+9
19=19