Đáp án:
Giải thích các bước giải:
3^2 . 179+43.36-79-9+6^2.57
=9.179+1548-79-9+36.57
=1611+1548-79-9+2052
=3459-79-9+2052
=3380-9+2052
=3371+2052
=5423
b) 2 .(7- 3^2020-3^2019):2^2+400
=2.(7-3):4+400
=2.4:4+400 =2.6:4+400
=8:4+400
=2+400
=402
a)55-7(x+3)=4^2-10
55-7(x+3)=16-10
55-7(x+3)=6
7(x+3)=55-6
7(x+3)=49
x+3=49:7
x+3=7
x=7-3
x=4
b)462:(10.x+2.5)=8 ²-2.11
462:(10x+10)=64-22
462:[10.x+10]=42
10.x+10=462:42
10.x+10=11
10x=11-10
10x=1
x=1/10