Respuesta :

In a triangle, all of the sides total to 180°. So we could write

180=90+(3x+4)+(5x-2)
subtract 90 from both sides
90=3x+4+5x-2
add the similar values
90=8x+2
subtract 2 from both sides
88=8x
divide both sides by 8
11=x

Answer: X=11