Question

Tìm X

a) 5 x (4 + 6 x X) = 290 b) X x 3,7 + X x 6,3 = 120 c) (15 x 24 – X) : 0,25 = 100 : 1/4

d) 128 x X – 12 x X – 16 x X = 5208000

e) 5 x X + 3,75 x X + 1,25 x X = 20

g) (84,6 – 2 x X) : 3,02 = 5,1

Answer 1

\(a,\) \(5.\left(4+6x\right)=290\)

\(4+6x=290:5\)

\(4+6x=58\)

\(6x=58-4\)

\(6x=54\)

\(x=54:6\)

\(x=9\left(tm\right)\)

Vậy ..................

\(b,x.3,7+x.6,3=120\)

\(x\left(3,7+6,3\right)=120\)

\(10x=120\)

\(x=120:10\)

\(x=12\left(tm\right)\)

Vậy ....................

c) \(\left(15.24-x\right):0,25=100:\dfrac{1}{4}\)

\(\left(360-x\right):\dfrac{1}{4}=400\)

\(360-x=400.\dfrac{1}{4}\)

\(360-x=100\)

\(x=360-100\)

\(x=260\left(tm\right)\)

Vậy ...................

Answer 2

a) 5. ( 4+6 . x ) = 290

( 4+6 . x ) = 290 : 5

4 + 6 . x = 58

6 .x = 58 - 4

6.x = 54

x = 54 : 6

x = 9

Answer 3

b) x . 3,7 + x . 6,3 = 120

x ( 3,7 + 6,3 ) = 120

x . 10 = 120

x = 120 : 10

x = 12

Answer 4

d) \(128x-12x-16x=5208000\)

\(x\left(128-12-16\right)=5208000\)

\(x.100=5208000\)

\(x=5208000:100\)

\(x=52080\left(tm\right)\)

Vậy ..........................

e) \(5x+3,75x+1,25x=20\)

\(x\left(5+3,75+1,25\right)=20\)

\(10x=20\)

\(x=20:10\)

\(x=2\left(tm\right)\)

Vậy .................

g) \(\left(84,6-2x\right):3,02=5,1\)

\(84,6-2x=5,1.3,02\)

\(84,6-2x=15,402\)

\(2x=84,6-15,402\)

\(2x=69,198\)

\(x=69,198:2\)

\(x=34,599\left(tm\right)\)

Vậy ............