Primer ejercicio
[tex]a + b = 90 \\ a = 3x + 10 \\ b = x \\ 90 = 3x + 10 + x \\ 90 = 4x + 10 \\ 80 = 4x \\ 20 = x \\ \\ a = 3(20) + 10 \\ = 60 + 10 \\ = 70 \\ \\ b = 20[/tex]
segundo ejercicio
[tex]a = x + 20 \: \: \: \: \: \: b = 2x \: \: \: \: \: c = 3x - 40 \\ a + b + c = 180 \\ x + 20 + 2x + 3x - 40 = 180 \\ 6x = 200 \\ x = \frac{100}{3} \\ \\ a = \frac{100}{3} + 20 \\ \\ = \frac{160}{3} \\ \\ b = 2( \frac{100}{3} ) \\ \\ = \frac{200}{3} \\ \\ c = 3( \frac{100}{3} ) - 40 \\ = 100 - 40 \\ 60[/tex]
