Ta có : ( x  + 5 ) ( x + 6 )

\(\Rightarrow\begin{cases}x+5=0\\x+6=0\end{cases}\)

\(\Rightarrow\begin{cases}x=-5\\x=-6\end{cases}\)

37/40=0,925; 19/25=0,76; còn câu cuối mình không hiểu

Em đặt PHYNIS CLUD

42% của 32 = 42% x 32 = 13,44                              

1b

\(\frac{1}{2}.\frac{1}{2}+\frac{1}{2}.\frac{1}{3} +\frac{1}{3}+\frac{1}{3}+\frac{1}{4}+\frac{1}{4}.\frac{1}{5}+\frac{1}{5}.\frac{1}{6}\)

\(=\frac{1}{4}+\frac{1}{6}+\frac{2}{3}+\frac{1}{4}+\frac{1}{20}+\frac{1}{30}\)

\(=\frac{5}{20}+\frac{5}{30}+\frac{20}{30}+\frac{5}{20}+\frac{1}{20}+\frac{1}{30}\)

\(=\left(\frac{5}{20}+\frac{5}{20}+\frac{1}{20}\right)+\left(\frac{5}{30}+\frac{20}{30}+\frac{1}{30}\right)\)

\(=\frac{11}{20}+\frac{26}{30}\)

\(=\frac{11}{20}+\frac{13}{15}\)

\(=\frac{17}{12}\)

a.

(x-1/4)^4=1/256

(x-1/4)^4=(1/4)^4

x-1/4=1/4

x=1/4+1/4

x=2/4

1b

22/5+51/9+11/4+3/5+1/3+1/4

=22/5+17/3+11/4+3/5+1/3+1/4

=(22/5+3/5)+(17/3+1/3)+(11/4+1/4)

=25/5+18/3+12/4

=5+6+3

=14