\(\Rightarrow\left(15.x\right)=3.60=180\Rightarrow x=180\div15=12\)

a) \(3M=1.2.3+2.3.3+...+48.49.3=1.2.3+2.3.\left(4-1\right)+...+48.49.\left(50-47\right)=1.2.3+2.3.4-1.2.3+...+48.49.50-47.48.49=48.49.50\Rightarrow M=\dfrac{48.49.50}{3}\Rightarrow M=39200\)

b) Tương tự câu a

\(3^{2x}.9^x=9^2.27\Rightarrow3^{2x}.3^{2x}=3^4.3^3\Rightarrow3^{4x}=3^7\Rightarrow4x=7\Rightarrow x=\dfrac{7}{4}\)

This place is school.

I heard that it is an old school.

Students usually go there.

I can learn many useful subjects here.

People like to go there becuse they want to widen their knowledge.

N = \(\dfrac{3^{30}.5^{30}}{3^{30}.5^{15}}=\dfrac{5^{30}}{5^{15}}=5^{15}\)

0,09 tấn

4,68 tấn

\(\widehat{yOt}=65^o\)

rách

402g

554g

2005g