Question

determine o valor de x.ajuda por favor !​

Answer 1

A soma dos ângulos internos de um triangulo deve ser igual a 180°.

c)

$(x-40)+(x+10)+(x-10)~=~180^\circ\\\\\\3x-40~=~180^\circ\\\\\\3x~=~180^\circ+40^\circ\\\\\\\boxed{x~=~\dfrac{220^\circ}{3}}$

d)

$(x-30)+x+x~=~180^\circ\\\\\\3x-30~=~180^\circ\\\\\\3x~=~210^\circ\\\\\\x~=~\dfrac{210^\circ}{3}\\\\\\\boxed{x~=~70^\circ}$