a) Ta có: $(3x+8x+70)^{\circ}=180^{\circ}$. Suy ra x = 10.
b) Ta có: $(4x+6)^{\circ}+(11x-6)^{\circ}=180^{\circ}$. Suy ra x = 12.
a) Ta có: $(3x+8x+70)^{\circ}=180^{\circ}$. Suy ra x = 10.
b) Ta có: $(4x+6)^{\circ}+(11x-6)^{\circ}=180^{\circ}$. Suy ra x = 12.