Question

9x²-7(x+4)(4-x)-(1-4x)²=15 решите

Answer 1

9x2 – 7(x+4)(4-x)-(1-4x)2=15
9x2-7(4x-x2+16-4x)-(1-8x+16x2)=15                             
9x2+7x2-112-1+8x-16x2=15                                        
8x=15+112+1
8x=128/:8
x=16