Since the graph given to us is a straight line we know that the value of it is 180° since the value of a straight line is always 180°. Now we have to solve for x and to do that we add the 2 values given to us and set it equal to 180°.
4x-4+4x=180
Now we combine the like terms on the left side of the equation.
8x-4=180
Now we have to add the 4 to both sides.
8x=184
Now to get the x by itself (find the value of x) we have to divide the 8 on both sides.
x=23
Now that we have found x we can plug it back into the equation for number 1 [(4x-4)] and solve to find the value of number 1.
4(23)-4=88
Answer: 88°
Hope this helps :)