Question

tìm x:
a) X-270:45=120

b) 575- ( 6x X+70 ) = 445

c) X - 105 : 21 = 15

d) 3200 : ( 405- x ) = 8

i) 43575 - 75 x X = 42450

e) 8,75 x X + 1,25 x X = 20
Ai làm đc câu nào thì giúp mik với:>

Answer 1

a) \(x-270:45=120\)

\(x-270=120.45\)

\(x-270=5400\)

\(x=5400+270\)

\(x=5670\)

_____

b) \(575-\left(6\times x+70\right)=445\)

\(6\times x+70=575-445\)

\(6\times x+70=130\)

\(6\times x=130-70\)

\(6\times x=60\)

\(x=60:6\)

\(x=10\)

_____

c) \(x-105:21=15\)

\(x-105=15.21\)

\(x-105=315\)

\(x=315+105\)

\(x=420\)

_____

d) \(3200:\left(405-x\right)=8\)

\(405-x=3200:8\)

\(405-x=400\)

\(x=405-400\)

\(x=5\)

_____

i) \(43575-75\times x=42450\)

\(75.x=43575-42450\)

\(75.x=1125\)

\(x=1125:75\)

\(x=15\)

_____

e) \(8,75\times x+1,25\times x=20\)

\(x\times\left(8,75+1,25\right)=20\)

\(x\times10=20\)

\(x=20:10\)

\(x=2\)

Answer 2

ko cần giải câu b đâu

Answer 3

a) x = 5670

b) x = 10

c) x = 420

d) x = 5

i) x = 15

e) x = 2