Câu 5: Tính nhanh:
2023 x 6 + 7 x 2023 – 2023 : =
Tính nhanh: 2023 x 28 + 2023 x 34 - 2023 x 52
\(2023\times28+2023\times34-2023\times52\)
\(=2023\times\left(28+34-52\right)\)
\(=2023\times10\)
\(=20230\)
`# \text {DNamNgV}`
`2023 \times 28 + 2023 \times 34 - 2023 \times 52`
`= 2023 \times (28 + 34 - 52)`
`= 2023 \times 10 `
`=20230`
giải
$\text{ 2023 x 28 + 2023 x 34 -23 x 52}$
$\text{= 2023 x (28+34-52)}$
$\text{ = 2023 x 10}$
$\text{ = 20230}$
Tính nhanh:
a]4 x 2030 + 2023 x 2 + 2023 + 3 x 2023
2030 × 4 +2023 × 2 + 3 × 2023
=8120 + 4046 + 6069
=18235
= 4x2023+2023x2+2023 x1 + 3x2023
=2023x (4+2+3+1)
= 2023 x 10
= 20230
cảm ơn bạn đã đọc!
4×2030 + 2 × 2030+3×2030 =4×2030+2×2030+3×2030 ×1= 2030×(4+2+3+1)=2030×10=20300
tính nhanh
(2022 x 2023 + 2024 x 21 + 2002 ) :( 2024 x 2023 - 2022 x 2023 )
Tính nhanh:
2022 x 2023 - 1/2023 x 2021 + 2022
\(\dfrac{2022\times2023-1}{2023\times2021+2022}\)
= \(\dfrac{\left(2021+1\right)\times2023-1}{2023\times2021+2022}\)
= \(\dfrac{2023\times2021+2023-1}{2023\times2021+2022}\)
= \(\dfrac{2023\times2021+2022}{2023\times2021+2022}\)
= 1
10.Tính bằng cách thuận tiện nhất: 94 x 2023 + 2023 : 1/6 nhanh giúp mình sáng mai mình nộp rồi
94.2023+2023:1/6
=94.2023+2023.6
=(94+6).2023
=100.2023
=202300
Tìm x,y thỏa mãn x^2 +5y^2 -4x -4xy +6y +5 = 0. Tính P=(x-3)^2023 + (y-2)^2023 +(x+y-5)^2023
Ta có:
\(x^2+5y^2-4x-4xy+6y+5=0\\\Rightarrow[(x^2-4xy+4y^2)-(4x-8y)+4]+(y^2-2y+1)=0\\\Rightarrow[(x-2y)^2-4(x-2y)+4]+(y-1)^2=0\\\Rightarrow(x-2y-2)^2+(y-1)^2=0\)
Ta thấy: \(\left\{{}\begin{matrix}\left(x-2y-2\right)^2\ge0\forall x,y\\\left(y-1\right)^2\ge0\forall y\end{matrix}\right.\)
\(\Rightarrow\left(x-2y-2\right)^2+\left(y-1\right)^2\ge0\forall x,y\)
Mà: \(\left(x-2y-2\right)^2+\left(y-1\right)^2=0\)
nên: \(\left\{{}\begin{matrix}x-2y-2=0\\y-1=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=2y+2\\y=1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=2\cdot1+2=4\\y=1\end{matrix}\right.\)
Thay \(x=4;y=1\) vào \(P\), ta được:
\(P=\left(4-3\right)^{2023}+\left(1-2\right)^{2023}+\left(4+1-5\right)^{2023}\)
\(=1^{2023}+\left(-1\right)^{2023}+0^{2023}\)
\(=1-1=0\)
Vậy \(P=0\) khi \(x=4;y=1\).
tìm x biết
\(\dfrac{x-2023}{6}\)\(+\dfrac{x-2023}{10}\)\(+\dfrac{x-2023}{15}\)\(+\dfrac{x-2023}{21}\)=\(\dfrac{8}{21}\)
\(\dfrac{x-2023}{6}+\dfrac{x-2023}{10}+\dfrac{x-2023}{15}+\dfrac{x-2023}{21}=\dfrac{8}{21}\)
\(\left(x-2023\right)\left(\dfrac{1}{6}+\dfrac{1}{10}+\dfrac{1}{15}+\dfrac{1}{21}\right)=\dfrac{8}{21}\)
\(\left(x-2023\right).\dfrac{8}{21}=\dfrac{8}{21}\)
\(x-2023=1\)
\(x=2024\)
Vậy..............
\(...\Rightarrow\left(x-2023\right)\left(\dfrac{1}{6}+\dfrac{1}{10}+\dfrac{1}{15}+\dfrac{1}{21}\right)=\dfrac{8}{21}\)
\(\Rightarrow\left(x-2023\right)\left(\dfrac{35+21+14+1}{210}\right)=\dfrac{8}{21}\)
\(\Rightarrow\left(x-2023\right).\dfrac{71}{210}=\dfrac{8}{21}\)
\(\Rightarrow\left(x-2023\right).\dfrac{71}{210}=\dfrac{8}{21}.\dfrac{210}{71}=\dfrac{80}{71}\)
\(\Rightarrow x-2023=\dfrac{80}{71}\Rightarrow x=\dfrac{80}{71}+2023=\dfrac{143713}{71}\)
\(\dfrac{x-2023}{6}+\dfrac{x-2023}{10}+\dfrac{x-2023}{15}+\dfrac{x-2023}{21}=\dfrac{8}{21}\)
\(\Leftrightarrow\left(x-2023\right).\left(\dfrac{1}{6}+\dfrac{1}{10}+\dfrac{1}{15}+\dfrac{1}{21}\right)=\dfrac{8}{21}\)
\(\Leftrightarrow\left(x-2023\right).\left(\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}\right)=\dfrac{4}{21}\)
\(\Leftrightarrow\left(x-2023\right).\left(\dfrac{1}{3.4}+\dfrac{1}{4.5}+\dfrac{1}{5.6}+\dfrac{1}{6.7}\right)=\dfrac{4}{21}\)
\(\Leftrightarrow\left(x-2023\right).\left(\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{7}\right)=\dfrac{4}{21}\)
\(\Leftrightarrow\left(x-2023\right).\left(\dfrac{1}{3}-\dfrac{1}{7}\right)=\dfrac{4}{21}\)
\(\Leftrightarrow x-2023=1\Leftrightarrow x=2024\)
Tính nhanh: \(\dfrac{7}{1`2}.\dfrac{2024}{2023}-\dfrac{7}{2023}.\dfrac{1}{2}\)
Có phải đề như này ko ?
`7/1^2`.`2024/2023-7/2023`.`1/2`
`#``\text{Lócc}`
`7/1.2 . 2024/2023 - 7/2023 . 1/2`
`= 7/2 . 2024/2023 - 7/2023 . 1/2`
`= 7/1 . 1/2 . 2024/2023 - 7/2023 . 1/2`
`= 7 . 1/2. (2024/2023 - 7/2023 )`
`= 7. 1/2 .2017/2023`
`= 7/2 . 2017/2023`
`= 14189/4046`
a, cho x, y là 2 số thoả mãn (2x - y + 7)\(^{2022}\) + |x - 1|\(^{2023}\) ≤ 0. Tính giá trị của biểu thức: P = x\(^{2023}\) + (y - 10)\(^{2023}\)
b, Tìm số tự nhiên x, y biết 25 - y\(^2\) = 8(x = 2023)\(^2\)
c, Tìm giá trị nhỏ nhất của biểu thức: P = (|x - 3| + 2)\(^2\) + |y + 3| + 2019
d, Tìm cặp số nguyên x, y biết: (2 - x)(x + 1) = |y + 1|
a: \(\left(2x-y+7\right)^{2022}>=0\forall x,y\)
\(\left|x-1\right|^{2023}>=0\forall x\)
=>\(\left(2x-y+7\right)^{2022}+\left|x-1\right|^{2023}>=0\forall x,y\)
mà \(\left(2x-y+7\right)^{2022}+\left|x-1\right|^{2023}< =0\forall x,y\)
nên \(\left(2x-y+7\right)^{2022}+\left|x-1\right|^{2023}=0\)
=>\(\left\{{}\begin{matrix}2x-y+7=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=2x+7=9\end{matrix}\right.\)
\(P=x^{2023}+\left(y-10\right)^{2023}\)
\(=1^{2023}+\left(9-10\right)^{2023}\)
=1-1
=0
c: \(\left|x-3\right|>=0\forall x\)
=>\(\left|x-3\right|+2>=2\forall x\)
=>\(\left(\left|x-3\right|+2\right)^2>=4\forall x\)
mà \(\left|y+3\right|>=0\forall y\)
nên \(\left(\left|x-3\right|+2\right)^2+\left|y+3\right|>=4\forall x,y\)
=>\(P=\left(\left|x-3\right|+2\right)^2+\left|y-3\right|+2019>=4+2019=2023\forall x,y\)
Dấu '=' xảy ra khi x-3=0 và y-3=0
=>x=3 và y=3