3x-x=(2x+4)-(x+4)? That is my answer but it might not be right
is the same thing here as the other triangles, the triangle below is an equilateral, the one above is an isosceles.
the <u>vertex</u> of the isosceles is 40°, so the twins angle at the <u>base</u> are (180 - 40)/2 = 70° = x each.
since the sides in the equilateral are all the same length, then 2y + 10 = x - y, but we already know what "x" is, so

The second one the unit rate is 2.05 i think