Question

Na figura abaixo, sabendo que r//s, qual o valor de x?


5°
10°
15°
20°
25°

Answer 1

Explicação passo-a-passo:

Esses ângulos são alternos internos logo são congruentes.

$2x+17^{\circ} =\dfrac{x}{3}+42^{\circ} \\\\2x-\dfrac{x}{3}=42^{\circ} -17^{\circ} \\\\\dfrac{6x-x}{3}=25^{\circ} \\\\ \dfrac{5x}{3}=25^{\circ}\\\\5x=25^{\circ}.3\\\\5x=75^{\circ}\\\\x=\dfrac{75^{\circ}}{5}\\\\\boxed{\boxed{x=15^{\circ}}}$