Question 1007732
We can solve this using two proportions, which will give us two equations to solve from...we have (using k and s for their ages NOW)...
{{{(k-6)/(s-6) = 6/5}}} and {{{(k+4) / (s+4) = 11/10}}}
If we cross-multiply these we get
5(k-6) = 6(s-6)
5k - 30 = 6s - 36
5k - 6s = -6
and
10(k+4) = 11(s+4)
10k + 40 = 11s + 44
10k - 11s = 4
Double the first one and subtract
10k - 11s = 4
-(10k - 12s = -12)
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s = 16
k = 18