1.

a) = 354

b) = -54

c) = -167

2.

A= -37

14,7+0,25.3,72-10,8=14,7+0,93-10,8=15,63-10,8=4,83

14,7 + 0,25 x 3,72 - 10,8 

= 14,7 + 0,93 - 10,8

= 4,83

14,7 + 0,25 x 3,72 - 10,8

= 14,7 + 0,93 - 10,8

= 15,63 - 10,8

= 4,83

k mình nhé mình trả lời nhanh nhất

\(14,7+0,25\times3,72-10,8\)
\(=14,7+0,93-10,8\)
\(=15,63-10,8\)
\(=4,83\)

14,7 + 0,35 x 3,78 - 10,8

=14,7 + 1,323 - 10,8        

= 16,023 - 10,8

= 5,223

14,7 + 0,35 x 3,78 - 10,8

=14,7 + 1,323 - 10,8        

= 16,023 - 10,8

= 5,223

5,223 và 1,1

\(1,\\ a,=\left(\dfrac{1}{4}\right)^3\cdot32=\dfrac{1}{64}\cdot32=\dfrac{1}{2}\\ b,=\left(\dfrac{1}{8}\right)^3\cdot512=\dfrac{1}{512}\cdot512=1\\ c,=\dfrac{2^6\cdot2^{10}}{2^{20}}=\dfrac{1}{2^4}=\dfrac{1}{16}\\ d,=\dfrac{3^{44}\cdot3^{17}}{3^{30}\cdot3^{30}}=3\\ 2,\\ a,A=\left|x-\dfrac{3}{4}\right|\ge0\\ A_{min}=0\Leftrightarrow x=\dfrac{3}{4}\\ b,B=1,5+\left|2-x\right|\ge1,5\\ A_{min}=1,5\Leftrightarrow x=2\\ c,A=\left|2x-\dfrac{1}{3}\right|+107\ge107\\ A_{min}=107\Leftrightarrow2x=\dfrac{1}{3}\Leftrightarrow x=\dfrac{1}{6}\)

\(d,M=5\left|1-4x\right|-1\ge-1\\ M_{min}=-1\Leftrightarrow4x=1\Leftrightarrow x=\dfrac{1}{4}\\ 3,\\ a,C=-\left|x-2\right|\le0\\ C_{max}=0\Leftrightarrow x=2\\ b,D=1-\left|2x-3\right|\le1\\ D_{max}=1\Leftrightarrow x=\dfrac{3}{2}\\ c,D=-\left|x+\dfrac{5}{2}\right|\le0\\ D_{max}=0\Leftrightarrow x=-\dfrac{5}{2}\)

3/4:X=1,2                             120,4+X=268,26

X=3/4:1,2                              X=268,26-120,4

X=0,625                                X=147,68

14,7+0,25x3,72-10,8=4.83

3/4x(2/3-1/5:3/5)=1/4

a/\(240\times20-\left(846+202\times2,5\right)\)
\(=4800-\left(846+505\right)\)
\(=4800-1351\)
\(=3449\)
b/\(2000+\left(32,4:3-2,8\right)\)
\(=2000+\left(10,8-2,8\right)\)
\(=2000+8\)
\(=2008\)
c/\(320\times1,25-\left(933+302\times3,5\right)\)
\(=400-\left(933+1057\right)\)
\(=400-1990\)
\(=-1590\)

Câu 1:

\(25\left(x-y\right)^2-16\left(x+y\right)^2\)

\(=\left[5\left(x-y\right)\right]^2-\left[4\left(x+y\right)\right]^2\)

\(=\left(5x-5y\right)^2-\left(4x+4y\right)^2\)

\(=\left(5x-5y-4x-4y\right)\left(5x-5y+4x+4y\right)\)

\(=\left(x-9y\right)\left(9x-y\right)\)

Bài 2:

a: ĐKXĐ: \(x\notin\left\{1;-\dfrac{1}{2}\right\}\)

b: \(P=\left(\dfrac{1}{x-1}-\dfrac{x}{1-x^3}\cdot\dfrac{x^2+x+1}{x+1}\right):\dfrac{2x+1}{x^2+1}\)

\(=\left(\dfrac{1}{x-1}+\dfrac{x}{\left(x-1\right)\left(x^2+x+1\right)}\cdot\dfrac{x^2+x+1}{x+1}\right)\cdot\dfrac{x^2+1}{2x+1}\)

\(=\left(\dfrac{1}{x-1}+\dfrac{x}{\left(x-1\right)\left(x+1\right)}\right)\cdot\dfrac{x^2+1}{2x+1}\)

\(=\dfrac{x+1+x}{\left(x-1\right)\left(x+1\right)}\cdot\dfrac{x^2+1}{2x+1}=\dfrac{x^2+1}{x^2-1}\)

c: Thay x=1/2 vào P, ta được:

\(P=\dfrac{\left(\dfrac{1}{2}\right)^2+1}{\left(\dfrac{1}{2}\right)^2-1}=\dfrac{5}{4}:\dfrac{-3}{4}=\dfrac{5}{4}\cdot\dfrac{-4}{3}=-\dfrac{5}{3}\)