a, = 5 - 4 = 1

b, \(\Leftrightarrow M=2\left(x+2\right)-x\left(x+2\right)\)

\(\Leftrightarrow M=\left(x+2\right)\left(2-x\right)\)

33 wirelessly

34 angry

35 nutrients?

36 Technology

1 will be play

2 have made

3 take

4 crashing

The aliens would be big and strong if the gravity was low.

This is the worst flood that the town has ever hit.

sửa :

công thức công suất : \(P=\dfrac{A}{t}\left(W\right)\)

công suất của 1 máy 200W là trong 1 giây máy thực hiện đc 200V

a, Công :

\(P=\dfrac{A}{t}\Rightarrow A=P\cdot t=1400\cdot38=53200\left(J\right)\)

b, Lực của máy nâng lên :

\(A=P\cdot h\Rightarrow P=\dfrac{A}{h}=\dfrac{53200}{10}=5320\left(N\right)\)

B

\(\dfrac{4}{7}\times\dfrac{21}{16}:\dfrac{5}{8}=\dfrac{4}{7}\times\dfrac{21}{16}\times\dfrac{8}{5}=\dfrac{6}{5}\)

\(\dfrac{15}{8}-\dfrac{4}{9}\times\dfrac{6}{8}+\dfrac{1}{6}=\dfrac{15}{8}-\dfrac{1}{3}+\dfrac{1}{6}=\dfrac{60}{24}-\dfrac{8}{24}+\dfrac{4}{24}=\dfrac{56}{24}=\dfrac{7}{3}\)

\(\dfrac{7}{15}+\left(\dfrac{5}{6}-\dfrac{1}{3}\right)=\dfrac{7}{15}+\dfrac{3}{6}=\dfrac{7}{15}+\dfrac{1}{2}=\dfrac{14}{30}+\dfrac{15}{30}=\dfrac{29}{30}\)