=945 * ( 238 + 1 ) - 1

944 + 945 * 238

=945 * 238 + 238

944 + 945 * 238

=1

\(\frac{\left(238+1\right)\cdot945-1}{945\cdot238+944}=\frac{238\cdot945+945-1}{945\cdot238+944}=\frac{945\cdot238+944}{945\cdot238+944}=1\)

\(=\frac{945x239-1}{944+945x\left(239-1\right)}=\frac{945x239-1}{944+945x239-945}=\frac{945x239-1}{945x239-1}=1\)

\(=\frac{945.\left(328+1\right)-1}{\left(945-1\right)+945.328}\)

\(=\frac{945.328+\left(945-1\right)}{\left(945-1\right)+945.328}=1\)

a: \(=145\cdot100-143\cdot100=2\cdot100=200\)

b: \(b=675\cdot a+674\)

TH1: a=1

=>b=675+674=1349

a,Ta có \(\frac{x}{6}=\frac{2}{3}\)

\(\Rightarrow3x=12\Rightarrow x=4\)

Vậy x = 4

b, \(\left(\frac{4}{7}+\frac{8}{9}\right)-\frac{5}{9}=\frac{4}{7}+\frac{8}{9}-\frac{5}{9}\)

\(=\frac{4}{7}+\left(\frac{8}{9}-\frac{5}{9}\right)\)

\(=\frac{4}{7}+\frac{1}{3}\)

\(=\frac{19}{21}\)

Bài 1 mình nhầm. x phần 6 = 4 phần 7 mới đúng. Cảm ơn bạn nhé

\(9,65\times0,4\times0,25\)

\(=\)\(9,65\times\left(0,4\times0,25\right)\)

\(=\)\(9,65\times0,1\)

\(=\)\(0,965\)

\(0,25\times40\times9,84\)

\(=\)\(\left(0,25\times40\right)\times9,84\)

\(=\)\(10\times9,84\)

\(=\)\(98,4\)

(9+1)+(8+2)+(7+3)+(6+4)+10+5

=10+10+10+10+10+5=45

9+3+2+1+7+8+5+10+6+4= (9+1)+(2+8)+(3+7)+(4+6)+5=10+10+10+10+5=10.4+5=40+5=45

a; \(\dfrac{21}{11}\) x \(\dfrac{22}{17}\) x \(\dfrac{68}{63}\)

= \(\dfrac{21\times11\times2\times17\times4}{11\times17\times21\times3}\)

= \(\dfrac{11\times17\times21}{11\times17\times21}\) x \(\dfrac{2\times4}{3}\)

= 1 x \(\dfrac{8}{3}\)

= \(\dfrac{8}{3}\)

b; \(\dfrac{5}{14}\) \(\times\) \(\dfrac{7}{13}\) x \(\dfrac{26}{25}\)

= \(\dfrac{5\times7\times2\times13}{7\times2\times13\times5\times5}\)

= \(\dfrac{5\times7\times2\times13}{5\times7\times2\times13}\) x \(\dfrac{1}{5}\)

= 1 x \(\dfrac{1}{5}\)

= \(\dfrac{1}{5}\)