Question

como substituir o X dessa equação pra achar o angulo(foto)
3x/5 + 105 + 4x - 17 = 180

12x/5 - 17 = 75

12x/5 = 92

12x = 92 . 5

12x = 460

X = 38,3

Answer 1

Explicação passo-a-passo:

$\sf \dfrac{3x}{5}+105^{\circ}+4x-17^{\circ}=180^{\circ}$

$\sf \dfrac{3x}{5}+4x+88^{\circ}=180^{\circ}$

$\sf \dfrac{3x}{5}+4x=180^{\circ}-88^{\circ}$

$\sf \dfrac{3x}{5}+4x=92^{\circ}$

$\sf 3x+5\cdot4x=5\cdot92^{\circ}$

$\sf 3x+20x=460^{\circ}$

$\sf 23x=460^{\circ}$

$\sf x=\dfrac{460^{\circ}}{23}$

$\sf x=20^{\circ}$

Assim:

$\sf A\hat{O}C=\dfrac{3x}{5}+105^{\circ}$

$\sf A\hat{O}C=\dfrac{3\cdot20^{\circ}}{5}+105^{\circ}$

$\sf A\hat{O}C=\dfrac{60^{\circ}}{5}+105^{\circ}$

$\sf A\hat{O}C=12^{\circ}+105^{\circ}$

$\sf \red{A\hat{O}C=117^{\circ}}$

Letra A