Question

Answer 1

\(a,315+x=721\\ \Leftrightarrow x=406\\ b,287-x=153\\ \Leftrightarrow x=134\\ c,x-419=260\\ \Leftrightarrow x=679\\ d,37x=3737\Leftrightarrow x=101\\ e,25\left(x+1\right)=100\\ \Leftrightarrow x+1=4\\ \Leftrightarrow x=3\)

Answer 2

a: x+315=721

=>x=721-315=406

b: 287-x=163

=>x=287-163=124

c: x-415=260

=>x=260+415=675

d: 37*x=3737

=>x=3737/37=102

e: =>x+1=4

=>x=3

Answer 3

a) 315 + x = 721

x = 721 - 315

x = 406

b) 287 - x = 133 (?)              287 - x = 153

x = 287 - 133                                 x = 287 - 153

x = 154                                           x = 134

(xl do mình ko thấy rõ đề bài)

c) x - 419 = 260

x = 260 + 419

x = 679

d) \(37\times x=3737\)

x = 3737 : 37

x = 101

e) \(25\times\left(x+1\right)=100\)

x + 1 = 100 : 25

x + 1 = 4

x = 4 - 1 

x = 3