Question 511557
s+t=10 t=10-s
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6s+12t=84
6s+12(10-s)=84
6s+120-12s=84
-6s=84-120
-6s=-36
s=6 six volt batteries
t=10-6=4 tewelve volt batteries
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6*6+12*4=84
36+48=84