Mọi người giúp mình với cần gấp lắm !
P=2/3–(–1/4)+3/5–7/45–(–5/9)+1/12+1/35
Q=(5–3/4+1/5)–(6+7/4–8/5)–(2–5/4+16/5)
Mọi người giúp mình với cần gấp lắm !
P=2/3–(–1/4)+3/5–7/45–(–5/9)+1/12+1/35
Q=(5–3/4+1/5)–(6+7/4–8/5)–(2–5/4+16/5)
Đáp án:
` P=2/3– (–1/4)+3/5–7/45– (–5/9)+1/12+1/35 `
`= 2/3 + 1/4 + 3/5 – 7/45 + 5/9 + 1/12 + 1/35`
`= ( 2/3 + 5/9 ) + ( 1/4 + 1/12 ) + (3/5 + 1/35 ) – 7/45 `
`= 11/9 + 4/12 + 22/35 – 7/45`
`= 639/315 = 71/35`
`Q=(5 – 3/4+1/5)–(6+7/4–8/5)–(2–5/4+16/5)`
`= 5-3/4 + 1/5 – 6 – 7/4 + 8/5 – 2 + 5/4 + 16/5`
`= (5-6-2) + (-3/4 – 7/4 +5/4) + ( 1/5 + 8/5 – 16/5)`
`= -3 -5/4-7/5`
`= -113/20`
`Go od luck !`
Đáp án:
$P=\dfrac{71}{35}\\
Q=\dfrac{-113}{20}$
Giải thích các bước giải:
$P=\dfrac{2}{3}-\left ( -\dfrac{1}{4} \right )+\dfrac{3}{5}-\dfrac{7}{45}-\left ( -\dfrac{5}{9} \right )+\dfrac{1}{12}+\dfrac{1}{35}\\
=\dfrac{2}{3}+\dfrac{1}{4} +\dfrac{3}{5}-\dfrac{7}{45}+\dfrac{5}{9} +\dfrac{1}{12}+\dfrac{1}{35}\\
=\left (\dfrac{2}{3} +\dfrac{5}{9} \right )+\left (\dfrac{1}{4} +\dfrac{1}{12} \right ) +\left (\dfrac{3}{5} +\dfrac{1}{35} \right )-\dfrac{7}{45}\\
=\left (\dfrac{6}{9} +\dfrac{5}{9} \right )+\left (\dfrac{3}{12} +\dfrac{1}{12} \right ) +\left (\dfrac{21}{35} +\dfrac{1}{35} \right )-\dfrac{7}{45}\\
=\dfrac{11}{9}+\dfrac{4}{12}+\dfrac{22}{35}-\dfrac{7}{45}\\
=\dfrac{11}{9}+\dfrac{1}{3}+\dfrac{22}{35}-\dfrac{7}{45}\\
=\dfrac{11}{9}+\dfrac{3}{9}+\dfrac{22}{35}-\dfrac{7}{45}\\
=\dfrac{14.35}{315}+\dfrac{22.9}{315}-\dfrac{7.7}{315}\\
=\dfrac{639}{315}\\
=\dfrac{71}{35}\\
Q=\left ( 5-\dfrac{3}{4}+\dfrac{1}{5} \right )-\left ( 6+\dfrac{7}{4}-\dfrac{8}{5} \right )-\left ( 2-\dfrac{5}{4}+\dfrac{16}{5} \right )\\
=5-\dfrac{3}{4}+\dfrac{1}{5} – 6-\dfrac{7}{4}+\dfrac{8}{5} – 2+\dfrac{5}{4}-\dfrac{16}{5}\\
=(5-6-2)+\left ( -\dfrac{3}{4}-\dfrac{7}{4}+\dfrac{5}{4} \right )+\left ( \dfrac{1}{5}+\dfrac{8}{5}-\dfrac{16}{5} \right )\\
=-3-\dfrac{5}{4}-\dfrac{7}{5}\\
=\dfrac{-60}{20}-\dfrac{25}{20}-\dfrac{28}{20}\\
=\dfrac{-113}{20}$