x+50=75                                                  x-25=50

     x =75-50                                                 x =50+25

     x =25                                                       x =75

Find x:

x+50=75                         x-25=50

Ai tk mk mk tk lại!

The number of people that have black hair is:

100% - 12% - 25% = 63%

There are: 600:100x63=378 ( people )

So the answer is 378 people have black hair.

The maximum value of \(P=\dfrac{x^2+2x+1}{x^2+1}\) is ........?
A. 2
B. 0
C. -1
D. -2

One rectangle with sides x and 3x. One isosceles right triangle with the length of leg x. What is the ratio of the area of the rectangle to that of the triangle ?

Calculate:

\(C=\dfrac{8-\dfrac{8}{5}+\dfrac{8}{25}-\dfrac{8}{125}}{9-\dfrac{9}{5}+\dfrac{9}{25}-\dfrac{9}{125}}:\dfrac{161616}{151515}\)

Find the value of \(n\) such that \(A=n^3-2n^2+2n-4\) is a prime number.

Compact:

\(\dfrac{2^2.3^2.4^2.5^2}{28800}\)

The result of a survey of the hair colour of 600 people are shown in this circle graph. How many people have black hair.

Solve the equation: \(x^3-3x^2+3x-1=0\)

Prove that:

\(\dfrac{12n+1}{30n+2}:d\) \(\left(d=1\right)\)

How many numbers \(x\) divided by 11 satisfy this equation:

\(999\le x\le1111\)

Find the suitable \(x\in N\) satisfy this fraction as a natural number:

\(\dfrac{2n+8}{n+2}\)

Prove that:

\(\dfrac{7x-21}{14x-42}=\dfrac{2}{4}\)

Mr.Joseph drives car from A to B at a constant speed. If the speeds of the car is increased by 20%, it takes him me one hour than the usual time. If the drives at the constant speed for the first 100km before increasing the speed by 30%, it also takes him one hour less than usual. This distance of AB is .... km?

Prove that:

\(\dfrac{99}{100}>\dfrac{1}{2^2}+\dfrac{1}{3^2}+...+\dfrac{1}{100^2}>\dfrac{99}{202}\)

We have:

\(P=\dfrac{2}{1.3}+\dfrac{2}{3.5}+...+\dfrac{2}{\left(2n+1\right)\left(2n+3\right)}\)

Prove that: \(P< 1,\forall n>0\)

Solve the equation: \(2x^4-x^3-5x^2+x+2=0\).

The volume of the cube below is ... \(cm^3\):

Calculate:

\(\dfrac{2}{7}-\left(\dfrac{3}{8}+\dfrac{9}{7}\right)\)

We have:

\(P=\dfrac{4n+1}{2n+3}\) . Find \(n\) so that \(P\) is a natural number.

Sorry! The result is too big!   

159753+753951+852456+258456=?

Ai tk mk mk tk lại

= 2023824

1597537896324475163252135230+1485324572277146532665217=?

Ai tk mk mk tk lại