Please help extremely important!!

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

Parabolas y=−2x^2 and y=2x^2+k intersect at points a and b that are in the third and the fourth quadrants respectively. find k if length of the segment ab is 5.