1.=545.(65+15-80)

=545.0

=0

2.=100:{250:[450-(4.125-4.25)]}

   =100:{250:[450-4.(125-25)]}

   =100:{250:[450-4.100]}

   =100:{250:50}

   =100:5

   =20

1. 545.65 + 545.15 - 80.445

= 545(65+15)-80.445

= 545.80-80.445

= 80.(545-445)

= 80.100

= 8000

312 + (146 -X ) =401

11- (15 + 21 ) + X- (25-9)

2- X +177 - (-5) 

X -12 = (-9) - 15 

a: \(=32-76=-44\)

b: \(=20-30+4^2=-10+16=6\)

d, \(1000:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}\)

\(=1000:\left\{250:\left[450-\left(4.125-4.25\right)\right]\right\}\)

\(=1000:\left\{250:\left[450-4.\left(125-25\right)\right]\right\}\)

\(=1000:\left[250:\left(450-400\right)\right]\)

\(=1000:\left(250:50\right)=1000:5=200\)

Chúc bạn học tốt!!!

Ta có : \(1000:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}\)

\(=1000:\left\{250:\left[450-\left(4.5^3-4.5^2\right)\right]\right\}\)

\(=1000:\left\{250:\left[450-4.5^2\left(5-1\right)\right]\right\}\)

\(=1000:\left[250:\left(450-400\right)\right]\)

\(=1000:\left(250:50\right)\)

\(=1000:5=200\)

Chúc bạn học tốt ^^

\(1000:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}\)

\(=1000:\left\{250:\left[450-\left(4.125-4.25\right)\right]\right\}\)

\(=1000:\left\{250:\left[450-4.\left(125-25\right)\right]\right\}\)

\(=1000:\left[250:\left(450-400\right)\right]\)

\(=1000:\left(250:50\right)\)

\(1000:5=200\)

a: \(=\left\{145-\left[130-10\right]:2\right\}\cdot5\)

\(=\left\{145-60\right\}\cdot5=85\cdot5=425\)

b: \(=100:\left\{250:\left[450-4\cdot125+4\cdot25\right]\right\}\)

\(=\dfrac{100}{250:\left[450-500+100\right]}=\dfrac{100}{250:50}=\dfrac{100}{5}=20\)

c: \(=355-5\cdot\left[64-\left(27-25\right)\right]=355-5\cdot\left[64-2\right]\)

\(=355-310=45\)

ai giúp mình với 

các góc nhọn,tù,vuông có bao nhiêu độ

minhf

a. 525

b. 

a. -82

b. 15