Question

[Nguyễn Ngọc Thuỳ Vy]

Tìm x biết:

a) 5 ( x+35)=515

b) (x+40).15=75.12

c) 460+85.4=(x+200):4

Tính nhanh:   (2³.9⁴+9³.45):(9².10-9²)

Answer 1

[Minh Hiền]

a. 5(x+35)=515

=> x+35=515:5

=> x+35=103

=> x = 103-35

=> x = 68

b. (x+40).15=75.12

=>(x+40).15=900

=>x+40=900:15

=>x+40=60

=>x=60-40

=>x=20

c.460+85.4=(x+200):4

=>460+340=(x+200):4

=>800=(x+200):4

=>800.4=x+200

=>3200=x+200

=>x=3200-200

=>x=3000

Answer 2

[Nguyễn Tiến Dũng]

5(x+35)=515

x+35=515/5

x+35=103

x=103-35

x=68