Đáp án là A Tính  2 5 x 1 2 : 1 3

a

câu 1: 12x13/5x24=12x13/5x12x2=13/5x2=13/10

câu 2 : 25x17+25x12/29x13+29x14

         =25x(17+12)/29x(13+14)

         =25.29/29.27

         =25/27

5000 k nha

500 nha

= 25 x  ( 1 + 86 + 12 + 1 + 100 )

= 25 x ( 87 +12 +1 + 100 )

= 25 x ( 99 +1 + 100)

= 25 x ( 100 +100)

= 25 x 200

= 5000

2500 nha k nha

mik ko bít

= 25 x ( 86 + 12 + 1 + 1 )

= 25 x ( 98 +1 +1 )

= 25 x (99 +1 )

= 25 x 100

= 2500

\(x^2-25=\left(x-5\right)\left(x+5\right)\\ x^2+10x+25=\left(x+5\right)^2\\ x^2-6x+xy-6y=x\left(x-6\right)+y\left(x-6\right)=\left(x+y\right)\left(x-6\right)\\ x^2-2x-y^2+1=\left(x-1\right)^2-y^2=\left(x-y-1\right)\left(x+y-1\right)\)

1675 : 25 x 12 = 804

1675:25x12

=67x12

=804

k mình nha

bằng 804

\(9.16^x+16.9^x=25.12^x\)

\(\Leftrightarrow9.\left(\frac{16}{9}\right)^x+16=25.\left(\frac{12}{9}\right)^x\)

\(\Leftrightarrow9.\left(\frac{4}{3}\right)^{2x}-25.\left(\frac{4}{3}\right)^x+16=0\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(\frac{4}{3}\right)^x=1=\left(\frac{4}{3}\right)^0\\\left(\frac{4}{3}\right)^x=\frac{16}{9}=\left(\frac{4}{3}\right)^2\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\)

=(5x-3)(5x+3)