C

C

có bị sai đề ko bạn sao vài chỗ ko có dấu cộng trừ nhân chia vậy??

12. (-47) + 12. (-19) + (-66). 88

= 12. [(-47) + (-19)] + (-66). 88

= 12. (-66) + (-66). 88

= (-66). (12 + 88)

= (-66). 100

= -6600

A = 12.(-47) + 12.(-19) + (-66).88

A = -12.(47 + 19)  - 66.88

A = -12.66 - 66.88

A = -66.(12 + 88)

A = -66. 100

A = - 6600

B1:

\(a.301^2=\left(300+1\right)^2=300^2+2.300.1+1^2\\ =90000+600+1=90601\\ b.88^2+2.88.12+12^2=\left(88+12\right)^2=100^2=10000\\ c.99.100=100^2-100=10000-100=9900\\ d,153^2+94.153+47^2=153^2+2.153.47+47^2=\left(153+47\right)^2=200^2=40000\)

B2:

\(A=x^2-20x+101\\ =x^2-2.x.10+10^2+1\\ =\left(x-10\right)^2+1\ge1\forall x\in R\left(Vì:\left(x-10\right)^2\ge0\forall x\in R\right)\\ \Rightarrow min_A=1\Leftrightarrow x-10=0\Leftrightarrow x=10\)

bằng 9/5

bang 9/5 

e. = 12 - 25 + 38 + 25 - 38 + 88  - 250 

    = ( -25 + 25) + (38 - 38) + ( 12 + 88) - 250

   = -150

f. = (-12).44 + 44.(-88)

 = 44 ( -12 -88 )

= 44 . 100

= 4400

g. = -48 + 54 -77 -24 + 48 + 77

= (-48 + 48) + (-77+77) + (54 -24)

= 30

h. = 11.(-42) + 11.(-26) + 42.11 + 42.26 -26.11 - 42.26

 = \([11.\left(-42\right)+11.42]+\left[11.\left(-26\right)-26.11\right]+[42.26-42.26]\)

= 11. (-52)

= - 572

\(e.-\left(-12+25-38\right)+\left(25-38+88\right)-250\\ =12-25+38+25-38+88-250\\ =\left(25-25\right)+\left(38-38\right)+\left(12+88\right)-250\\ =0+0+100-250=-150\)

\(f.\left(-12\right)\cdot\left(67-23\right)+44\cdot\left(-88\right)\\ =\left(-12\right)\cdot44+44\cdot\left(-88\right)\\ =44\cdot\left[-12+\left(-88\right)\right]\\ =44\cdot\left(-100\right)=-4400\)

\(g.\left(-48+54-77\right)-\left(24-48-77\right)\\ =-48+54-77-24+48+77\\ =\left(48-48\right)+\left(54-24\right)+\left(77-77\right)\\ =0+30+0=30\)

\(h.11\cdot\left(-42-26\right)+42\cdot\left(11+26\right)-26\cdot11-42\cdot26\\ =11\cdot\left(-68\right)+42\cdot37-26\cdot11-42\cdot26\\ =-748+1554-286-1092=-572\)

88 + 12 =100

88 + 12 = 100

bằng 100 bạn

88+12=100