Question

bài 10: tìm x biết

a) 14 x X + X x 26=2520

b) X x 3/4 + X x 5/4=7/8

Answer 1

a) \(14\times X+X\times26=2520\)

\(X\times\left(14+26\right)=2520\)

\(X\times40=2520\)

\(X=2520:40\)

\(X=63\)

b) \(X\times\dfrac{3}{4}+X\times\dfrac{5}{4}=\dfrac{7}{8}\)

\(X\times\left(\dfrac{3}{4}+\dfrac{5}{4}\right)=\dfrac{7}{8}\)

\(X\times\dfrac{8}{4}=\dfrac{7}{8}\)

\(X\times2=\dfrac{7}{8}\)

\(X=\dfrac{7}{8}:2\)

\(X=\dfrac{7}{16}\)

Answer 2

giúp em nha

 

Answer 3

a) \(14.x+x.26=2520\)

\(\left(14+26\right).x=2520\)

\(40.x=2520\)

\(x=2520:40\)

\(x=63\)

Answer 4

a, 14 \(\times\) \(x\) + \(x\) \(\times\) 26 = 2520

     \(x\) \(\times\) ( 14 + 26) = 2520

      \(x\) \(\times\) 40 = 2520

       \(x\)         = 63

b, \(x\) \(\times\) \(\dfrac{3}{4}\) + \(x\) \(\times\) \(\dfrac{5}{4}\) = \(\dfrac{7}{8}\)

    \(x\) \(\times\) ( \(\dfrac{3}{4}\) + \(\dfrac{5}{4}\)) = \(\dfrac{7}{8}\)

    \(x\) \(\times\) 2 = \(\dfrac{7}{8}\)

     \(x\)        = \(\dfrac{7}{8}\) : 2

     \(x\)        =  \(\dfrac{7}{16}\)