a+b+c+d=786
[tex]b = \frac{3}{4} \times a[/tex]
[tex]c = \frac{2}{3} \times b - 16 = \frac{2}{3} \times \frac{3}{4} \times a - 16 \\ = \frac{1}{2} \times a - 16[/tex]
[tex]d = \frac{c}{2} = \frac{\frac{1}{2} \times a - 16}{2} [/tex]
[tex]a + \frac{3}{4} \times a + \frac{1}{2} \times a - 16 + \frac{\frac{1}{2} \times a - 16}{2} = 786[/tex]
[tex]a + \frac{3a}{4} + \frac{a}{2} - 16 + \frac{ \frac{a}{2} - 16}{2} = 786[/tex]
[tex]a + \frac{3a}{4} + \frac{a}{2} - 16 + \frac{{a} }{4} - 8 = 786[/tex]
4a+3a+2a+a-16-8=786
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4
[tex] \frac{10a}{4} - 24 = 786 |+ 24[/tex]
[tex] \frac{5a}{2} = 810 | \times 2[/tex]
[tex]5a = 1620 | \div 5[/tex]
[tex]a = 324 = > d = \frac{324}{4} - 8 = 81 - 8 = 73[/tex]
