Question

Determinati produsul axbxc ,stiind ca : a+b=90 , b+c=21 , a+c=75

Answer 1

a + b = 90
b + c = 21
a + c = 75
2a + 2b + 2c = 186
2 ( a + b + c ) = 186
a + b + c = 186 : 2
a + b + c + 93
90 + c = 93
c = 93 - 90
c = 3
b + c = 21
b + 3 = 21
b = 21-3
b = 18
a + c = 75
a = 75 - c
a = 75 - 3
a = 72
produsul  a x b x c = 72 x 18 x 3 = 1296 x 3 = 3888