Question

Answer 1

Bài 2:

a: \(x-10=-8\)

=>x=-8+10=2

b: \(565-13x=370\)

=>13x=565-370=195

=>x=15

c: \(x\cdot\left(-8\right)=\left(-7\right)\cdot\left(-6\right)-2\)

=>\(x\cdot\left(-8\right)=42-2=40\)

=>\(x=\dfrac{40}{-8}=-5\)

Bài 5:

Đặt \(A=2^2-2^3+2^4-2^5+...-2^{99}+2^{100}\)

=>\(2A=2^3-2^4+2^5-2^6+...-2^{100}+2^{101}\)

=>\(2A+A=2^3-2^4+...+2^{101}+2^2-2^3+2^4-...+2^{100}\)

=>\(3A=2^{101}+4\)

=>\(A=\dfrac{2^{101}+4}{3}\)

\(S=3+2^2-2^3+2^4-2^5+...-2^{99}+2^{100}\)

=>\(S=3+A=\dfrac{9+2^{101}+4}{3}=\dfrac{2^{101}+13}{3}\)