a/ 60x45-60x15-45x60+45x15

=(60x45-60x45)-(60x15-45x15)=0-15x(60-45)=-15x15=-225

b/68x12+68x32-32x68-12=68x12-12=12x67=804

c/-17x33+17x5+33x17-33x5

=5x(17-33)=5x(-16)=-80

a/(2+x)(7-x)=0

=> x+2=0 hoac 7-x=0

=> x=-2 hoac x=7

b/104x.(6-x)=0

=> x.(6-x)=0

=> x=0 hoac 6-x=0 => x=6

c//2x/+/x-14/=61

Vi x>14 nen : 2x+x-14=61

=> 3x=61+14=75

=> x=25

d//6-x/=2

=> 6-x=2 hoac 6-x=-2

=>x=4 hoac x=8

em moi lop 6 nhung con chua hoc den dang nay

Vì ot là tia p/g nên:

xot=toy=100:2=50

\(\Leftrightarrow\)xot=50

doan cuoi bi sai minh sua lai nhe :

Xet tam giac vuong NQP co : NQ²+QP²=NP²

=> NP²=3²+1²=10

=> NP=\(\sqrt{10}\)

Lần sau ban vẽ hình đẹp tí nha

seven là 7,fifty là 15 dễ mà :D

a/PTHH: 2Fe+6HCL------>2FeCl₃+3H₂

b/nFe=5,6/56=0,1(mol)

nHCL=14,6/36,5=0,4(mol)

Ta co : nFe/2 =0,05<nHCL/6≃0,06

=> nHCL du

=>nHCL=3nFe=0,3(mol)

mHCL=0,3.36,5=10,95(g)

c/nFeCl₃=nFe=0,1(mol)

mFeCl₃=0,1.162,5=16,25(g)

M la gi ban

x(x²-1)=6

=>x³-x-6=0

=>x³-2x²+2x²-4x+3x-6=0

=>x²(x-2)+2x(x-2)+3(x-2)=0

=>(x²+2x+3)(x-2)=0

TH1: x²+2x+3=0

=>(x²+2x+1)+2=0

=>(x+1)²+2≥2>0

=> pt vo nghiem

TH2: x-2=0

=>x=2

Vay nghiem cua phuong trinh la {2}

A