\(F=\left(2^0+2+2^2+2^3\right).2^0.2.2^2.2^3\)

\(F=\left(1+2+4+8\right).1.2.4.8\)

\(F=15.1.2.4.8\)

\(F=960\)

biaif toán này được 2 

nếu đúng k nha

78-18=60

x³ - 7x - 6 = 0

=> x³ + 2x² + x² + 2x - 3x² - 6x - 3x - 6 = 0

=> x² (x + 2) + x .(x + 2) - 3x(x + 2) - 3(x + 2) = 0

=> (x + 2) .(x² + x - 3x - 3) = 0

=> (x + 2) . [x (x + 1) - 3(x + 1)] = 0

=> (x + 2)(x + 1)(x - 3) = 0

=> x + 2 = 0 => x = -2

hoặc x + 1 = 0 => x = -1

hoặc x - 3 = 0 => x = 3

                                           Vậy x = 3, x = -1, x = -2

\(=\frac{35}{36}\)

Đặt \(A=\frac{3}{4.5}+\frac{3}{5.6}+\frac{3}{6.7}+..+\frac{3}{19.20}\)

\(A=3\left(\frac{1}{4.5}+\frac{1}{5.6}+\frac{1}{6.7}+...+\frac{1}{19.20}\right)\)

\(A=3\left(\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+...+\frac{1}{19}-\frac{1}{20}\right)\)

\(A=3\left(\frac{1}{4}-\frac{1}{20}\right)\)

\(A=\frac{3}{5}\)

Ủng hộ mk nha !!! ^_^