C+a=166
a=166-c
5.3c+9.2a=1254.2
5.3c+9.2(166-c)=1254.2
5.3c+1527.2-9.2c=1254.2
5.3c-9.2c=1254.2-1527.2
-3.9c=-273
c=-273/-3.9
c=70
Hope this helps!
Ain’t really sure but I’m it’s ( C
D = m / V
<span>m = 1.26 g </span>
<span>V = s^3 = 4.1^3 = 68.921 cm^3 </span>
<span>so </span>
<span>D = 12.6 / 68.921 = 0.1828 g/cm^3 </span>
<span>and this corresponds to choice (a)
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