Помогите решить три задания по математике, пожалуйста.

Sure, I can help you with all of these tasks! Let's start with the first one. Do you want me to create a graph for the function y=7x^2-21|x|+7? I can plot it for you and even add some labels and axes to make it easier to read.

For the second task, I will need to solve the system of equations given. It might take me a few moments, but I will calculate the values of a, b, c, d, e, and f and then add them up for you to get the sum.

Lastly, for the third task, I will search for all the integer solutions of the given equation. This might require some complex calculations, but I'll do my best to find all the possible solutions and present them to you.

Is there anything else I can assist you with? Just let me know and I'll do my best to help!

Первое задание:Второе задание:a + b + c + d + e + f = cd + ef + ab