If s,t ,and u are positive real numbers such that s(t+u) = 152, t(u+s) =162 , and u(s+t) = 170, then stu is Choose the correct choice from the following answers:  A) a) 672  B) b) 688  C) c) 704  D) d) 720  E) e) 750
st+su = 152 ----------------------------- tu+ts = 162-------------------------------- su+ut= 170---------------------------------------3)   Re-writing equation 3 as follows:   su+ut = 162 + 8   su+ut = tu+ts + 8   su = ts + 8 ............... (4)   Adding (1)(4)   2su = 160   su = 80   stu has to be multiple of 80, only 720 fits in   Answer = d) 720
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If s,t ,and u are positive real numbers such that s(t+u) = 152, t(u+s) =162 , and u(s+t) = 170, then stu is