Respuesta :

0.45(x  + 1.6) +  5x  = 18
0.45x + 0.72 + 5x = 18
5.45x = 18 - 0.72 =  17.28
x = 17.28 / 5.45

x =  3.17 answer
0.45(x+1.6)+5x = 18

Expanding 0.45x+0.45*1.6+5x = 18

Regrouping 0.45x+5x = 18-0.45*1.6

So 5.45x = 18-0.72
x = 17.28/5.45 = 3.17

Ans is B