Question 266551
Let z = Zack and s = Salman
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Zack is 4 times the age as Salman 
translates as
(i) {{{z = 4s}}}
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Zack is also 3 years older than Salaman
translates as
(ii) {{{z = s + 3}}}
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actually substitution is better here.
put (i) into (ii) to get
(iii) {{{4s = s + 3}}}
subtract s to get
(iv) {{{3s = 3}}}
and now divide to get
(v) {{{s = 1}}}
This means that salman = 1 and zack = 4