Question

Tính
A) \(\frac{15}{34}+\frac{7}{21}+\frac{19}{34}-1\frac{15}{17}+\frac{2}{3}\)
B) \(\left(-2\right)^3\times\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)
Tìm x
A) \(4\frac{1}{3}:\frac{\chi}{4}=6:0,3\)
B) \(\left(2^3:4\right)\times2^{\left(\chi+1\right)}=64\)

Answer 1

Answer 2

Answer 3

Tính:

b) \(\left(-2\right)^3.\left(\frac{3}{4}-0,25\right):\left(2\frac{1}{4}-1\frac{1}{6}\right)\)

\(=\left(-2\right)^3.\left(\frac{3}{4}-\frac{1}{4}\right):\left(\frac{9}{4}-\frac{7}{6}\right)\)

\(=\left(-8\right).\frac{1}{2}:\frac{13}{12}\)

\(=\left(-4\right):\frac{13}{12}\)

\(=-\frac{48}{13}.\)

Tìm x

a) \(4\frac{1}{3}:\frac{x}{4}=6:0,3\)

⇒ \(\frac{13}{3}:\frac{x}{4}=20\)

⇒ \(\frac{x}{4}=\frac{13}{3}:20\)

⇒ \(\frac{x}{4}=\frac{13}{60}\)

⇒ \(x.60=4.13\)

⇒ \(x.60=52\)

⇒ \(x=52:60\)

⇒ \(x=\frac{13}{15}\)

Vậy \(x=\frac{13}{15}.\)

b) \(\left(2^3:4\right).2^{x+1}=64\)

⇒ \(\left(8:4\right).2^{x+1}=64\)

⇒ \(2.2^{x+1}=64\)

⇒ \(2^{x+1}=64:2\)

⇒ \(2^{x+1}=32\)

⇒ \(2^{x+1}=2^5\)

⇒ \(x+1=5\)

⇒ \(x=5-1\)

⇒ \(x=4\)

Vậy \(x=4.\)

Chúc bạn học tốt!