\(B=\left(5x-11\right)^2-\left(10x-22\right)\left(5x-9\right)+\left(5x-9\right)^2\)
\(=\left(5x-11\right)^2-2\left(5x-11\right)\left(5x-9\right)+\left(5x-9\right)^2\)
\(=\left[\left(5x-11\right)-\left(5x-9\right)\right]^2\)
\(=\left(-2\right)^2=4\)
BT3: Tìm x
\(a,\left(x+2\right)^2-9=0\)
\(b,x^2-2x+1=25\)
\(c,\left(5x+1\right)^2-\left(5x-3\right)\left(5x+3\right)=30\)
\(d,\left(x-1\right)\left(x^2+x+1\right)+x\left(x+2\right)\left(2-x\right)=5\)
\(\left(x-2\right)\left(x^2+6x-11\right)^2=\left(5x^2-10x=1\right)^2\)
Tìm \(x\):
\(8\)) \(1-\left(x-6\right)=4\left(2-2x\right)\)
\(9\))\(\left(3x-2\right)\left(x+5\right)=0\)
\(10\))\(\left(x+3\right)\left(x^2+2\right)=0\)
\(11\))\(\left(5x-1\right)\left(x^2-9\right)=0\)
\(12\))\(x\left(x-3\right)+3\left(x-3\right)=0\)
\(13\))\(x\left(x-5\right)-4x+20=0\)
\(14\))\(x^2+4x-5=0\)
Chứng minh đẳng thức sau \(\left(5x-11\right)^2+\left(4-5x\:\right)^2+2\left(5x\:-11\right)\left(4-5x\:\right)=49\)
BÀI 1: GIẢI CÁC PHƯƠNG TRÌNH SAU
a) \(\left(2x-1\right)^2=49\)
b) \(\left(5x-3\right)^2-\left(4x-7\right)^2=0\)
c) \(\left(2x+7\right)^2-9\left(x+3\right)^2\)
d) \(\left(x+2\right)^2=9\left(x^2-4x+4\right)\)
e) \(4\left(2x+7\right)^2-9\left(x+3\right)^2=0\)
f) \(\left(5x^2-2x+10\right)^2=\left(3x^2+10x-8\right)^2\)
rút gọn
P=\(\left(5x+2\right).\left(2-5x\right)-\left(x-3\right).\left(x^2+3x+9\right)+x\left(x^2+21x\right)-23\)
BT9: Tìm x biết
\(9,\left(2x-5\right)^2-\left(x+1\right)^2=0\)
\(10,\left(x+3\right)^2-x^2=45\)
\(11,\left(5x-4\right)^2-49x^2=0\)
\(12,16\left(x-1\right)^2-25=0\)
làm tiếp tục giúp mình nha:
\(\left(x^3+1\right)-5x^2+3x+9\)
=\(\left(x^3+1\right)-5x^2-5x+\left(5x-1+3x+9\right)\)
=???????????????
Giải các phương trình sau
\(a.\left(3x+2\right)^2-\left(3x-2\right)^2=5x+8\)
\(b.3\left(x-2\right)^2+9\left(x-1\right)=3\left(x^2+x-3\right)\)
\(c.\left(x+3\right)^2-\left(x-3\right)^2=6x+18\)
\(d.\left(x-1\right)^3-x\left(x+1\right)^2=5x\left(2-x\right)-11\left(x+2\right)\)
