Question

1.Thực hiện các phép tính sau

a)42.57+43.42-600

b)2².5²-64:2³

c)120-[100-(5-2)³]

d)(10²+11²+12²) : (13²+14²)

2. Tìm x biết 

a)91-5.(5+x)=61

b)[(x+34)-50].2=56

Answer 1

a)

42.57 + 43.42 - 600

=42.(57+43)-600

=42.100-600

=4200-600

=3700

Answer 2

2².5²-64:2³

=4.25-64:8

=100-8

=92

Answer 3

120-[100-(5-2)³

=120-[100-27]

=120-73

=47

Answer 4

(10²+11²+12²):(13²+14²)

=(100+121+144+:(169+196)

=365:365

=1

Answer 5

Bài 2:

a) 91-5.(5+x)=61

5.(5+x)=91-61

5.(5+x)=30

5+x=30:5

5+x=6

x=6-5

x=1

Answer 6

[(x+34)-50].2=56

[(x+34)-50]=56:2

[(x+34)-50]=28

x+34=28+50

x+34=78

x=78-34

x=44