Question

afla numerele a+a=b,b+b=c,c+c-d,d+64=80

Answer 1

d= 80 - 64
d= 16
c + c = d
8 + 8 = 16
c = 8
b + b = 8
4 + 4 = 8
b = 4
a + a = b
a + a = 4
2+2 =  4 
a= 2

Answer 2

d+64=80; d=80-64; d=16; c+c=16; c=8; b+b=8; b=4; a+a=4; a=2;