\(0,4\text{×}96+1,6\text{×}25\)

\(=0,4\text{×}96+4\text{×}0,4\text{×}25\)

\(=0,4\text{×}96+0,4\text{×}\left(4\text{×}25\right)\)

\(=0,4\text{×}96+0,4\text{×}100\)

\(=0,4\left(100+96\right)\)

\(=0,4\text{×}196\)

\(=78,4\)

Học tốt

\(\dfrac{16\text{×}25+44\text{×}100}{29\text{×}96+142\text{×}48}\)

\(=\dfrac{16\text{×}25+44\text{×}25\text{×}4}{29\text{×}48\text{×}2+142\text{×}48}=\dfrac{16\text{×}25+\left(44\text{×}4\right)25}{\left(29\text{×}2\right)48+142\text{×}48}=\dfrac{16\text{×}25+176\text{×}25}{58\text{×}48+142\text{×}48}=\dfrac{25\left(16+176\right)}{48\left(58+142\right)}=\dfrac{25\text{×}192}{48\text{×}200}=\dfrac{4800}{9600}=\dfrac{48}{96}=\dfrac{1}{2}\)

5. Jana : My brother can play the guitar well , and he also composes music . I find him really amazing What do you think of heavy metal ? ( amaze)

st1 = 1 + 2 = 3

st2 = 3 + 4 = 7

st3 = 7 + 6 = 13

st4 = 13 + 8 = 21

st5 = 21 + 10 = 31

Vậy số tiếp theo là của dãy số 1 ; 3 ; 7 ; 13 ; 21 là số 31

\(\left(x-7\right)\) x \(\left(6-x\right)\) = 0

⇒ 2 thừa số sẽ bằng 0

Do đó:

\(x-7=0\)

       \(x=0+7\)

       \(x=7\)

\(x-6=0\)

       \(x=0+6\)

       \(x=6\)

Vậy:

\(x=7\) và \(x=6\)