Question

1. Tìm x biết:

a. 4.(x - 3)² - (2x - 1).(2x + 1) = 10

b. (x - 4)² - (x - 2).(x + 2) = 6

Answer 1

tth làm ko hay để a làm

Answer 2

a)\(4\left(x-3\right)^2-\left(2x-1\right)\left(2x+1\right)=10\)

\(< =>4\left(x^2-6x+9\right)-\left(4x^2-1\right)=10\)

\(< =>4x^2-24x+36-4x^2+1=10\)

\(< =>-24x+36+1-10=0\)

\(< =>-24x=-27\)

\(< =>x=\frac{9}{8}\)

\(S=\left\{\frac{9}{8}\right\}\)

Answer 3

\(\left(x-4\right)^2-\left(x-2\right)\left(x+2\right)=6\)

\(< =>x^2-8x+16-\left(x^2-4\right)=6\)

\(< =>x^2-8x+16-x^2+4=6\)

\(< =>-8x=-14\)

\(< =>x=\frac{7}{4}\)

\(S=\left\{\frac{7}{4}\right\}\)