\(a,75\cdot20,9+5^2\cdot20,9=20,9\left(75+25\right)=20,9\cdot100=2090\\ b,86\cdot15+150\cdot1,4=150\left(8,6+1,4\right)=150\cdot10=1500\\ c,93\cdot32+14\cdot16=32\left(93+7\right)=32\cdot100=3200\\ d,98,6\cdot199-990\cdot9,86=98,6\left(199-99\right)=98,6\cdot100=9860\\ e,-8\cdot40+2\cdot108+24=8\left(-40+27+3\right)=8\cdot\left(-10\right)=-80\\ f,993\cdot98+21\cdot331-50\cdot99,3=993\left(98-5+7\right)=993\cdot100=99300\)

3A:

a: \(75\cdot20.9+5^2\cdot20.9\)

\(=20.9\cdot100\)

=2090

b: \(86\cdot15+150\cdot1.4\)

\(=86\cdot15+15\cdot14\)

\(=15\cdot100=1500\)

c: \(93\cdot32+14\cdot16\)

\(=93\cdot32+32\cdot7\)

=3200

c) 93.32+14.16=93.2.16+14.16=16.(186+14)=16.200=3200

e)-8.40+2.108+24=24(9+1)-320=240-320=-80

b)86.15+150.1,4=86.15+15.14=15(86+14)=15.100=1500

d)98,6.199-990.9,86=98,6.199-99.98,6=98,6(199-99)=98,6.100=9860

f)993.98+21.331-50.99,3=993.(98+7-5)=993.100=99300

a: =-29x100=-2900

b: \(=\left(215-5\cdot80+5\cdot50+60\right):53=\dfrac{125}{53}\)

a: =-29x(165-65)=-29x100=-2900

b: \(=\left[215-5\cdot30-60\right]:53=0\)

(14568+3579)-(14563+3564)

= 14568+3579-14563-3564

=(14568-14563)+(3579-3564)

=5+15=20

Tích giúp mình nha

b) Ta có: \(86\cdot15+150\cdot1.4\)

\(=86\cdot15+14\cdot15\)

\(=15\left(86+14\right)\)

=1500

c) Ta có: \(93\cdot32+14\cdot16\)

\(=186\cdot16+14\cdot16\)

\(=16\left(186+14\right)\)

\(=16\cdot200=3200\)