Question

Помогите решить 100=20-d•13•7

Answer 1

100 = 20 - d *13 * 7
100 = 20  - 91d
91d = 20 -100
91d= -80
d= (-80) : 91
d = $- \frac{80}{91}$
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$100 = 20 - (- \frac{80}{91} ) * 13*7 \\ \\ 100 = 20 - (- \frac{80*13*7}{91*1*1} ) \\ \\ 100 = 20 - (- \frac{80*91}{91*1} ) \\ \\ 100 = 20-(-80) \\ \\ 100= 20+80 \\ \\ 100=100$