Transform the given system
x'₁ = 4x₁ - 10x₂
x'₂ = 7x₁ - 7x₂
into a single differential equation of second order for x_1.
A. x"₁ - 4x'₁ - 28x₁ = 0
B. x"₁ + 3x'₁ + 42x₁ = 0
C. x"₁ + 3x'₁ + 35x₁ = 0
D. x"₁ + 11x'₁ + 35x₁ = 0
E. x"₁ + 11x'₁ + 42x₁ = 0