a) 40 × x = 1400;

x = 1400 : 40

x = 35

a)40 x 35 =1400

b) 2665 : 13 = 205

a/ x= 1400:40

   x=35

b/x=205.13

x=2665

a) 40 nhân x = 1400

x=1400:40

x=35

b)x:13=205

x=205x13

x=2665

chúc bn học tốt

kết quả là

35 đúng thì k

\(40xX=1400\)

       \(X=1400:40\)

      \(X=35\)
\(K\)

\(NHA~~~!!!\)

40*x=1400

    x=1400:40

    x=35

k mih nha,mih nhanh nhat do

\(9576:x=1400-1372\)
\(\Rightarrow9576:x=28\)
\(\Rightarrow x=9576:28\)
\(\Rightarrow x=342\)

9576 : x = 28

           x= 9576 : 28

           x= 342

\(\text{9576:X=1400-1372}\)

\(\text{9576:X=28}\)

        \(\text{X=}9576:28\)

        \(\text{X=}342\)

\(Suyra:\text{X=}342\)

a) 40 x X = 1400

           X = 1400:40

           X = 35

b) x : 13 = 205

          x = 205 x 13

          x = 2665

a, 40 x \(x\) = 1400

       \(x\) = 1400 : 40

       \(x\) = 35

b, \(x\) : 13 = 205

           \(x\) = 205 x 13

           \(x\) = 2665

a, 40 x X = 1400

X = 1400 : 40

X = 35

b, X : 13 = 205

X = 205 x 13

X = 2665

x chia hết cho 35,60,15=>x\(\in\)BC(35,60,15)

BCNN(35,60,15)=2².3.5.7=420

BC(35,60,15)=B(420)={0,420,840,1260,1680,...}

Mà 1000<x<1400=>x=1260

Vậy x=1260

x:y:z =1:2:3 =>\(\frac{x}{1}=\frac{y}{2}=\frac{z}{3}\)

=> \(\frac{x+y+z}{1+2+3}=\frac{x^2+y^2+z^2}{^{1^2+2^2+3^2}}=\frac{1400}{14}=100\)

=>\(^{x^2=100\cdot1^2=100=>x=10}\)

=>\(y^2=100\cdot2^2=400=>y=20\)

=>\(z^2=100\cdot3^2=900=>z=30\)

Vậy x=10, y=20 và z=30