>>>КОД>>>
import matplotlib.pyplot as plt
import math

x_def = [0]
y_def = [0]
h = math.log(7, math.e) / 10000
i = 0
while 1:
    if x_def[i] > math.log(7, math.e):
        break
    x_def.append(x_def[i] + h)
    y_def.append(y_def[i] + h * (math.log(pow(math.e, y_def[i]) + x_def[i] - 4 * y_def[i] * y_def[i] * math.log(x_def[i] * y_def[i] + 1, math.e), math.e)))
    i += 1
print(y_def[len(y_def) - 1])
plt.plot(x_def, y_def)
plt.show()

>>> решение: y(ln7) = 0.9131244388017861