Question 908979
b+ 2 = (3/4)(s+2)
b = (3/4)s + (3/2) - 2 = {{{(3/4)s - 1/2}}}
b -2 = (2/3)(s-2)
{{{(3/4)s - 1/2}}} - 2 = (2/3)s - 4/3
{{{(9/12)s - (8/12)s = -4/3 + 1/2 + 2}}} |Multiplying thru by 12 so as all denominators = 1
9s - 8s = -16 + 6 + 24
s = 14, sister's age NOW, boy is 10. {{{b+ 2 = (3/4)16}}}using 1st EQ to find b