Tìm x biết: (5 - 2x)(2x + 7) = 4x^2 - 25

Tim x biet:
a. (5-2x)(2x+7)=4x^2-25
b. x^3+27+(x+3)(x-9)=0
c. 4(2x+7)^2-9(x+3)^2=0