16.(-3)+93+27 = 72

16.(-3)+93-27 = 18

206TCN>220SCN

gửi text   ?

Bài 1:

Bài 2:

a. $12-45-55+88=(12+88)-(45+55)=100-100=0$

b. $78+120+(-80)+(-18)=78+120-80-18$

$=(78-18)+(120-80)=60+40=100$

c. $(-5)^2+5.24+71.5=5.5+5.24+71.5$

$=5(5+24+71)=5(29+71)=5.100=500$

d.

$24(-16)+(-16)75-16=24(-16)+(-16).75+1(-16)$

$=(-16)(24+75+1)=(-16).100=-1600$

\(A=\left[x+\left(x+7\right)\right]-\left[\left(x+4\right)-\left(x-4\right)\right]\)

\(A=\left(x+x+7\right)-\left(x+4-x+4\right)\)

\(A=\left(2x+7\right)-\left(x-x+4+4\right)\)

\(A=2x+7-8\)

\(A=2x-1\)

\(B=x\left\{\left(x-3\right)-\left[\left(x+3\right)-\left(-x-2\right)\right]\right\}\)

\(B=x\left\{\left(x-3\right)-\left[x+3-\left(-x\right)+2\right]\right\}\)

\(B=x\left[\left(x-3\right)-\left(x+3+x+2\right)\right]\)

\(B=x\left(x-3-2x+5\right)\)

\(B=x\left(x-2x-3+5\right)\)

\(B=x\left(-x+2\right)\)

\(B=-x^2+2x\)

\(B=2x-x^2\)

Nhưng mà mình k bt ss kiểu j

\(A=2+3+3^2+...+3^{100}\)

\(A=2+\left(3+3^2+3^3\right)+...+\left(3^{98}+3^{99}+3^{100}\right)\)

\(A=2+1\left(3+3^2+3^3\right)+...+3^{97}\left(3+3^2+3^3\right)\)

\(A=3+13+...+3^{97}.13\)

=> A chia 13 dư 2 (bạn sửa cái số 3 hàng cuối thành số 2 hộ mk )

\(2250\)

a. 6x = -60 

<=> x = -10

b. x : 3 -12 = -27 

<=> x : 3 = -15 

<=> x = -45