a) 2⁸

b) 10⁵

c) 8³ . 6³ . 7³

d) a⁹

e) 10⁹

f) 2x⁵

Lời giải:

a. $=2^8$

b. $=10^5$

c. $=8^3.6^3.7^3=(8.6.7)^3=336^3$

d. $=a^9$

e. $=10000.10^3.100=10^4.10^3.10^2=10^{4+3+2}=10^9$

f. $=(2x)^5$

Bài \(2\)

\(a)\) \(2.2.2.2.2.2.2.2=2^8\)

\(b)\) \(10.10.10.10.10=10^5\)

\(c)\) \(8.8.8.6.6.7.7.7=8^3.6^2.7^3\)

\(d)\) \(a.a.a.a.a.a.a.a.a=a^9\)

\(e)\) \(10000 . 10 . 10 . 10 . 100\)

\(=10^4.10.10.10.10^2=10^9\)

\(f)\) \(2x.2x.2x.2x.2x=\left(2x\right)^5\)

a) \(2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\cdot2\)

\(=2^{1+1+1+1+1+1+1+1}\)

\(=2^8\)

b) \(10\cdot10\cdot10\cdot10\cdot10\)

\(=10^{1+1+1+1+1}\)

\(=10^5\)

c) \(8\cdot8\cdot8\cdot6\cdot6\cdot6\cdot7\cdot7\cdot7\)

\(=8^{1+1+1}\cdot6^{1+1+1}\cdot7^{1+1+1}\)

\(=8^3\cdot6^3\cdot7^3\)

\(=\left(8\cdot6\cdot7\right)^3\)

\(=336^3\)

d) \(a\cdot a\cdot a\cdot a\cdot a\cdot a\cdot a\cdot a\cdot a\)

\(=a^{1+1+1+1+1+1+1+1+1}\)

\(=a^9\)

e) \(10000\cdot10\cdot10\cdot10\cdot100\)

\(=10^4\cdot10\cdot10\cdot10\cdot10^2\)

\(=10^{4+1+1+1+2}\)

\(=10^9\)

f) \(2x\cdot2x\cdot2x\cdot2x\cdot2x\)

\(=\left(2x\right)^{1+1+1+1+1}\)

\(=\left(2x\right)^5\)

\(=32x^5\)

\(a,(x^3-x+1)(2x+1)+(x-1)(x+2)\)

\(=2x^4-2x^2+2x+x^3-x+1+x^2-x+2x-2\)

\(=2x^4+x^3+(-2x^2+x^2)+(2x-x-x+2x)+(1-2)\)

\(=2x^4+x^3-x^2+2x-1\)

\(b,(2x+a)(2x-3a)-5a(x+3)\)

\(=4x^2+2ax-6ax-3a^2-5ax-15a\)

\(=4x^2+(2ax-6ax-5ax)-3a^2-15a\)

\(=4x^2-9ax-3a^2-15a\)

Chúc bạn học tốt

a, \(\left(x^3-x+1\right)\left(2x+1\right)+\left(x-1\right)\left(x+2\right)\)

\(=2x^4+x^3-2x^2-x+2x+1+x^2+2x-x-2\)

\(=2x^4+x^3-x^2+2x-1\)

b, \(\left(2x+a\right)\left(2x-3a\right)-5a\left(x+3\right)\)

\(=4x^2-6xa+2ax-3a^2-5ax-15a\)

\(=4x^2-9ax-3a^2-15a\)

a,\(\left(x^3-x+1\right)\left(2x+1\right)+\left(x-1\right)\left(x+2\right)\)

\(=2x\left(x^3-x+1\right)+1\left(x^3-x+1\right)+x\left(x+2\right)-1\left(x+2\right)\)

\(=2x^4-2x^2+2x+x^3-x+1+x^2+2x-x-2\)

\(=2x^4+\left(-2x^2+x^2\right)+\left(2x-x+2x-x\right)+x^3+1-2\)

\(=2x^4-x^2+2x+x^3-1\)

b,\(\left(2x+a\right)\left(2x-3a\right)-5a\left(x+3\right)\)

\(=2x\left(2x-3a\right)+a\left(2x-3a\right)-5a\left(x+3\right)\)

\(=4x^2-6ax+2ax-3a^2-5ax-15a\)

\(=4x^2+\left(-6ax+2ax-5ax\right)-3a^2-15a\)

\(=4x^2-9ax-3a^2-15a\)

(2x)(2x)(2x)(2x)

=(2.2.2.2).(x.x.x.x)

=2⁴.x⁴

=(2x)⁴

\(b,N\left(x\right)=\left(4x^5-4x^5\right)+x^4-2x^3-3x^2+\left(3x-5x\right)+1\\ =x^4-2x^3-3x^2-2x\\ c,P\left(x\right)=\left(-2x^6+2x^6\right)+x^5+\left(-2x^4+2x^4\right)+2x^3-x+5\\ =x^5+2x^3-x+5\)

a: \(P\left(x\right)=5x^5-4x^4+2x^2+3x+6\)

\(Q\left(x\right)=-x^5+2x^4-2x^3+3x^2+x+\dfrac{1}{4}\)

b: \(P\left(x\right)+Q\left(x\right)=4x^5-2x^4-2x^3+5x^2+4x+\dfrac{25}{4}\)

Trước hết, ta rút gọn các đa thức:

- Q(x) = 4x3 – 2x + 5x2 - 2x3 + 1 - 2x3

Q(x) = (4x3- 2x3- 2x3) – 2x + 5x2 + 1

Q(x) = 0 – 2x + 5x2 + 1

Q(x) = – 2x + 5x2 + 1

- R(x) = - x2 + 2x4 + 2x - 3x4 – 10 + x4

R(x) = - x2 + (2x4- 3x4+ x4) + 2x – 10

R(x) = - x2 + 0 + 2x – 10

R(x) = - x2 + 2x – 10

Sắp xếp các hạng tử của đa thức sau theo lũy thừa giảm dần của biến ta có:

Q(x) = 5x2 – 2x + 1

R(x) = - x2 + 2x – 10

g(x) = -5 + 3x⁹ - 2x + 3x² + x⁶ + 2x - 3x³ - 3x²

= -5 + (-2x + 2x) + (3x² - 3x²) - 3x³ + x⁶ + 3x⁹

= -5 - 3x³ + x⁶ + 3x⁹

g(x) = -5 + 3x⁹ - 2x + 3x² + x⁶ + 2x - 3x³ - 3x²

= -5 + (-2x + 2x) + (3x² - 3x²) - 3x³ + x⁶ + 3x⁹

= -5 - 3x³ + x⁶ + 3x⁹