d: =-60-15=-75

c: =36+9=45

1 Tính nhanh

a) \(-14+12+\left(-12\right)\left(2^3-7\right)\)

\(=-14+\left[12+\left(-12\right)\right].1\)

\(=-14+0.1\)

\(=-14+0=-14\)

b) \(\left(-5\right)+2\left(-15\right)-\left(-3\right)+\left|-10\right|\)

\(=\left(-5\right)+\left(-30\right)-\left(-3\right)+10\)

\(=\left(-35\right)-\left(-3\right)+10\)

\(=\left(-32\right)+10\)

\(=-22\)

c) \(68.\left(12+32\right)-32.\left(68-12\right)\)

\(=68.44-32.56\)

\(=2992-1792\)

\(=1200\)

d) \(89-\left(-43\right)-32\)

\(=132-32\)

\(=100\)

e) \(-12.\left(-6\right)^2+\left(-4\right)^3.12\)

\(=-12.36+64.12\)

\(=\left(-12+12\right).\left(36+64\right)\)

\(=0+100\)

\(=100\)

a ) ( - 14 ) + 12 + ( - 12 ) . ( 2³ - 7 )

= - 2 + ( - 12 ) . ( 8 - 7 )

= - 2 + ( - 12 ) . 1

= - 2 + ( - 12 )

= - 14

= -32 .64 -64.68

= 64.(-32-68)

= 64. -100

= -6400

= 12.23+32.23

=23.(12+32)

=23.44

= 1012

Câu 12: B

Câu 13: C

Câu 14: A

C12 B

C13 C

C14 A

Bài 1 :

a) \(...=45\left(56+44\right)-500=45.100-500=4500-500=4000\)

b) \(...=3^2.6-6^{18}+1=45+1-6^{18}=46-6^{18}\)

c) \(...=756\left(66+48-14\right)=756.100=75600\)

d) \(...=8.15-\left(149-7^2\right)=120-\left(149-49\right)=120-100=20\)

Bài 2 :

a) \(x-21=46\Rightarrow x=21+46\Rightarrow x=87\)

b) \(2^x.4=128\Rightarrow2^x=32\Rightarrow2^x=2^5\Rightarrow x=5\)

c) \(3x+27=162\Rightarrow3x=162-27\Rightarrow3x=135\Rightarrow x=45\)

d) \(4x-8=4^{2023}.4^{2021}\)

\(\Rightarrow4x-8=4^{2023+2021}\)

\(\Rightarrow4x-8=4^{4044}\)

\(\Rightarrow4x=4^{4044}+8\)

\(\Rightarrow x=\left(4^{4044}+8\right):4\)

\(\Rightarrow x=4^{4043}+2\)

12 x 68 + 12 x 32 + 100

= 12 x (68 + 32) + 100

= 12 x 100 + 100

= 1200 + 100

= 1300

Thanks you so much