rút gọn biểu thức \(\left(5-3x\right)\left(5+3x\right)-\left(x+1\right)^3\)
Rút gọn các biểu thức sau
\(c,\left(3x+1\right)^2-2\left(3x+1\right)\left(3x+5\right)+\left(3x+5\right)^2\)
\(\left(3x+1\right)^2-2\left(3x+1\right)\left(3x+5\right)+\left(3x+5\right)^2\)
\(=\left[\left(3x+1\right)-\left(3x+5\right)\right]^2\)
\(=\left(3x+1-3x-5\right)^2\)
\(=\left(-4\right)^2=16\)
rút gọn biểu thức \(\left(5-3x\right)^2+\left(x+2\right)^2+x\left(3-4x\right)\)
\(\left(3x-5\right)^2+\left(x+2\right)^2+x\left(3-4x\right)\)
\(=9x^2-30x+25+x^2+4x+4+3x-4x^2\)
\(=6x^2-23x+29\)
\(=25-30x+9x^2+x^2+4x+4+3x-12x^2=-2x^2-23x+29\)
Rút gọn biểu thức:
\(3x\left(x+5\right)-\left(3x+18\right)\left(x-1\right)\)
\(3x\left(x+5\right)-\left(3x-18\right)\left(x-1\right)=3x^2+15x-3x^2+21x-18\)
\(=36x-18\)
Rút gọn biểu thức sau :
\(5\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(5\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(=5\left(4x^2-4x+1\right)+4\left(x^2+3x-x-3\right)-2\left(25-30x+9x^2\right)\)
\(=20x^2-20x+5+4x^2+12x-4x-12-50+60x-18x^2\)
\(=6x^2+48x-57\)
\(5\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(=5\left(4x^2-4x+1\right)+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(=5\left(4x^2-4x+1\right)+4\left(x-1\right)\left(x+3\right)-2\left(25-3x+9x^2\right)\)
\(=20x^2-20x+5+4\left(x-1\right)\left(x+3\right)-2\left(25-30x+9x^2\right)\)
\(=20x^2-20x+5+4x^2+8x-12-50+60x-18x^2\)
\(=6x^2+48x-57\)
Rút gọn các biểu thức :
a, \(\left(3x+5\right)^2+\left(3x-5\right)^2-\left(3x+2\right)\left(3x-2\right)\)
b, \(2x\left(2x-1\right)^2-3x\left(x+3\right)\left(x-3\right)-4x\left(x+1\right)^2\)
\(c,\left(x+y-z\right)^2+2\left(z-x-y\right)\left(x+y\right)+\left(x+y\right)^2\)
\(a,\left(3x+5\right)^2+\left(3x-5\right)^2-\left(3x+2\right)\left(3x-2\right)=9x^2+30x+25+9x^2-30x+25-9x^2+4=9x^2+54\)
\(b,BT=2x\left(4x^2-4x+1\right)-3x\left(x^2-9\right)-4x\left(x^2+2x+1\right)=8x^3-8x^2+2x-3x^3+27x-4x^3-8x^2-4x=x^3-16x^2+25x\)
\(c,BT=\left(x+y-z\right)^2-2\left(x+y-z\right)\left(x+y\right)+\left(x+y\right)^2=\left(x+y-z-x-y\right)^2=z^2\)
Rút gọn biểu thức:
\(\left(x+3\right)^2+\left(2x+1\right)\left(3x-5\right)-2x\left(3-x\right)+4x+25\)
Rút gọn biểu thức
\(\left(3x+5\right)^2+\left(3x-5\right)^2-\left(3x+2\right).\left(3x-2\right)\)
Rút gọn biểu thức
\(\left(3x+5\right)^2+\left(3x-5\right)^2-\left(3x+2\right).\left(3x-2\right)\)
Rút gọn các biểu thức sau:
\(a,\left(3x+1\right)^2-2\left(3x+1\right)\left(3x-5\right)+\left(3x-5\right)^2\)
\(b,\left(3x^2-y\right)^2-\left(2x^2+y\right)^2\)
\(a,\left(3x+1\right)^2-2\left(3x+1\right)\left(3x-5\right)+\left(3x-5\right)^2=\left(\left(3x+1\right)-\left(3x-5\right)\right)^2=6^2=36\)
\(b,\left(3x^2-y\right)^2-\left(2x^2+y\right)^2=\left(3x^2-y-2x^2-y\right)\left(3x^2-y+2x^2+y\right)=\left(x^2-2y\right).5x^2\)
a. BT= ((3x+1) - (3x-5))2=62=36
b. BT = (3x2-y-2x2-y). (3x2- y + 2x2+ y) = (x2-2y).5x2
a) \(\left(3x+1\right)^2-2\left(3x+1\right)\left(3x-5\right)+\left(3x-5\right)^2\)
\(=\left[\left(3x+1\right)^2-\left(3x+1\right)\left(3x-5\right)\right]-\left[\left(3x+1\right)\left(3x-5\right)-\left(3x-5\right)^2\right]\)
\(=\left[\left(3x+1\right)\left(3x+1-3x+5\right)\right]-\left[\left(3x+1-3x+5\right)\left(3x-5\right)\right]\)
\(=\left[6\left(3x+1\right)\right]-\left[6\left(3x-5\right)\right]\)
\(=6\left(3x+1-3x+5\right)\)
\(=6.6=36\)