Question

tìm x:

e) 4x^2 - 4x + 1 = (5 - x)^2

f) (2x - 3)^2 = x^2 + 10x + 25

g) x^2 (x - 1) - 4x^2 + 8x - 4 = 0

h) (x + 2)^2 - 4x^2 + 16 = 0

i) (4x^2 - 3x - 18)^2 = (4x^2 + 3x)^2

giúp với ạa

Answer 1

\(e,4x^2-4x+1=\left(5-x\right)^2\\ \left(2x-1\right)^2-\left(5-x\right)^2=0\\ \left(2x-1-5+x\right)\left(2x-1+5-x\right)=0\\ \left(3x-6\right)\left(x+4\right)=0\\ \)

\(\left[\begin{array}{} 3x-6=0\\ x+4=0 \end{array} \right.\)\(\Leftrightarrow\)\(\left[\begin{array}{} x=2\\ x=-4 \end{array} \right.\)

Answer 2

\(f,\left(2x-3\right)^2-4x^2+8x-4=0\\ \left(2x-3\right)^2-\left(2x-2\right)^2=0\\ \left(2x-3-2x+2\right)\left(2x-3+2x-2\right)=0\\ -1\left(4x-5\right)=0\\ x=\dfrac{5}{4}\)

Answer 3

\(h,\left(x+2\right)^2-4x^2+16=0\\ \left(x+2\right)^2-4\left(x^2-4\right)=0\\ \left(x+2\right)^2-\left(x-2\right)\left(x+2\right)=0\\ 4\left(x+2\right)\left(x+2-x+2\right)=0\\ 4\left(x+2\right)4= 0\\ x+2=0\\ x=-2\)