Tính các tổng sau :
a) \(\left[\left(-13\right)+\left(-15\right)\right]+\left(-8\right)\)
b) \(500-\left(-200\right)-210-100\)
c) \(-\left(-129\right)+\left(-119\right)-301+12\)
d) \(777-\left(-111\right)-\left(-222\right)+20\)
Những câu hỏi liên quan
Tính các tổng sau :
a) \(\left[\left(-8\right)+\left(-7\right)+\left(-10\right)\right]\)
b) \(555-\left(-333\right)-100-80\)
c) \(-\left(-229\right)+\left(-219\right)-401+12\)
d) \(300-\left(-200\right)-\left(-120\right)+18\)
a, \(\left[\left(-8\right)+\left(-7\right)+\left(-10\right)\right]\) = -25
b, 555-(-333)-100-80 = 555 + 333 - 100 - 80
= 888-100-80
= 788 - 80
= 708
c, -(-229) +(-219) - 401 +12 = 229 - 219 - 401 + 12
= 10 + 12 - 401
= 22 - 401
= -379
d, 300 - (-200) - (-120) + 18 = 300 + 200 + 120 +18
= 620 + 18
= 638
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Tính :
a) \(5+\left(-7\right)+9+\left(-11\right)+13+\left(-15\right)\)
b) \(\left(-6\right)+8+\left(-10\right)+12+\left(-14\right)+16\)
a)
\(5+\left(-7\right)+9+\left(-11\right)+13+\left(-15\right)\)
\(=\left[5+\left(-7\right)\right]+\left[9+\left(-11\right)\right]+\left[13+\left(-15\right)\right]\)
\(=\left(-2\right)+\left(-2\right)+\left(-2\right)=-6\)
b)
\(\left(-6\right)+8+\left(-10\right)+12+\left(-14\right)+16\)
\(=\left[\left(-6\right)+8\right]+\left[\left(-10\right)+12\right]+\left[\left(-14\right)+16\right]\)
\(=2+2+2=6\)
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Tính các tích sau:
\(a = \left( { - 2} \right).\left( { - 3} \right)\)
\(b = \left( { - 15} \right).\left( { - 6} \right)\)
\(c = \left( { + 3} \right).\left( { + 2} \right)\)
\(d = \left( { - 10} \right).\left( { - 20} \right)\)
\(a = \left( { - 2} \right).\left( { - 3} \right) = 2.3 = 6\)
\(b = \left( { - 15} \right).\left( { - 6} \right) = 15.6 = 90\)
\(c = \left( { + 3} \right).\left( { + 2} \right) = 3.2 = 6\)
\(d = \left( { - 10} \right).\left( { - 20} \right) = 10.20 = 200\).
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text{Thực hiện các phép tính sau một cách hợp lý:}a) left(10^2+11^2+12^2right):left(13^2+14^2right)b) 1.2.3...9-1.2.3...8-1.2.3...7.8^2c) dfrac{left(3.4.2^{16}right)^2}{11.2^{13}.4^{11}-16^9}d) 1152-left(374+1152right)+left(-65+374right)e) 13-12+11+10-9+8-7-6+5-4+3+2-1
Đọc tiếp
\(\text{Thực hiện các phép tính sau một cách hợp lý:}\)
\(a\)) \(\left(10^2+11^2+12^2\right):\left(13^2+14^2\right)\)
\(b\)) \(1.2.3...9-1.2.3...8-1.2.3...7.8^2\)
\(c\)) \(\dfrac{\left(3.4.2^{16}\right)^2}{11.2^{13}.4^{11}-16^9}\)
\(d\)) \(1152-\left(374+1152\right)+\left(-65+374\right)\)
\(e\)) \(13-12+11+10-9+8-7-6+5-4+3+2-1\)
Giải các phương trình sau:
a) \(8 - \left( {x - 15} \right) = 2.\left( {3 - 2x} \right)\);
b) \( - 6\left( {1,5 - 2u} \right) = 3\left( { - 15 + 2u} \right)\);
c) \({\left( {x + 3} \right)^2} - x\left( {x + 4} \right) = 13\);
d) \(\left( {y + 5} \right)\left( {y - 5} \right) - {\left( {y - 2} \right)^2} = 5\).
a) \(8 - \left( {x - 15} \right) = 2.\left( {3 - 2x} \right)\)
\(8 - x + 15 = 6 - 4x\)
\( - x + 4x = 6 - 8 - 15\)
\(3x = - 17\)
\(x = \left( { - 17} \right):3\)
\(x = \dfrac{{ - 17}}{3}\)
Vậy nghiệm của phương trình là \(x = \dfrac{{ - 17}}{3}\).
b) \( - 6\left( {1,5 - 2u} \right) = 3\left( { - 15 + 2u} \right)\)
\( - 9 + 12u = - 45 + 6u\)
\(12u - 6u = - 45 + 9\)
\(u = \left( { - 36} \right):6\)
\(6u = - 36\)
\(u = - 6\)
Vậy nghiệm của phương trình là \(u = - 6\).
c) \({\left( {x + 3} \right)^2} - x\left( {x + 4} \right) = 13\)
\(\left( {{x^2} + 6x + 9} \right) - \left( {{x^2} + 4x} \right) = 13\)
\({x^2} + 6x + 9 - {x^2} - 4x = 13\)
\(\left( {{x^2} - {x^2}} \right) + \left( {6x - 4x} \right) = 13 - 9\)
\(2x = 4\)
\(x = 4:2\)
\(x = 2\)
Vậy nghiệm của phương trình là \(x = 2\).
d) \(\left( {y + 5} \right)\left( {y - 5} \right) - {\left( {y - 2} \right)^2} = 5\)
\(\left( {{y^2} - 25} \right) - \left( {{y^2} - 4y + 4} \right) = 5\)
\({y^2} - 25 - {y^2} + 4y - 4 = 5\)
\(\left( {{y^2} - {y^2}} \right) + 4y = 5 + 4 + 25\)
\(4y = 34\)
\(y = 34:4\)
\(y = \dfrac{{17}}{2}\)
Vậy nghiệm của phương trình là \(y = \dfrac{{17}}{2}\).
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tính A=\(\left[\frac{100}{2}\right]+\left[\frac{100}{2^2}\right]+...+\left[\frac{100}{2^6}\right]\)
B=\(\left[\sqrt{1}\right]+\left[\sqrt{2}\right]+...+\left[\sqrt{500}\right]\)
C=\(\left[\frac{-12}{3}\right]+\left[\frac{-11}{3}\right]+...+\left[\frac{12}{3}\right]\)
Thực hiện các phép tính sau:
a) 4.25 - 12.5 + 170 : 10;
b) (7 + 33 : 32).4 - 3;
c) 12 : {400 : [500 - (125 + 25.7)]};
d) 168 + {[2.(24 + 32) -2560] : 72}.
a)
4 . 25 – 12 . 25 + 170 : 10
= (4 . 25) – (12 . 25) + (170 : 10)
= 100 - 300 + 17
= -183
b)
(7 + 33 + 32) . 4 – 3
= (7 + 27 + 9) .4 – 3
= 43 . 4 – 3
= (43 . 4) – 3
= 45
c)
12 : {400 : [500 – (125 + 25 . 7)}
= 12 : {400 : [500 – (125 + 175)}
= 12 : (400: 200)
= 12 : 2
= 6
d)
168 + {[2.(24 + 32) - 2560] : 72}.
= 168 + [2 . (16 + 9) – 1] : 49
= 168 + 49: 49
= 168 + 1
= 167
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a)
4 . 25 – 12 . 25 + 170 : 10
= (4 . 25) – (12 . 25) + (170 : 10)
= 100 - 300 + 17
= -183
b)
(7 + 33 + 32) . 4 – 3
= (7 + 27 + 9) .4 – 3
= 43 . 4 – 3
= (43 . 4) – 3
= 45
c)
12 : {400 : [500 – (125 + 25 . 7)}
= 12 : {400 : [500 – (125 + 175)}
= 12 : (400: 200)
= 12 : 2
= 6
d)
168 + {[2.(24 + 32) - 2560] : 72}.
= 168 + [2 . (16 + 9) – 1] : 49
= 168 + 49: 49
= 168 + 1
= 167
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Xem thêm câu trả lời
a) Aleft(frac{-5}{11}right).frac{7}{15}.left(frac{11}{-5}right).left(-30right)b) Bleft(-frac{1}{6}right).left(frac{-15}{19}right).left(frac{38}{45}right)c) C left(frac{-5}{9}right).frac{3}{11}+left(frac{-13}{18}right).frac{3}{11}d) D left(2frac{2}{15}.frac{9}{17}.frac{3}{32}right):left(frac{-3}{27}right)
Đọc tiếp
a) A=\(\left(\frac{-5}{11}\right).\frac{7}{15}.\left(\frac{11}{-5}\right).\left(-30\right)\)
b) B=\(\left(-\frac{1}{6}\right).\left(\frac{-15}{19}\right).\left(\frac{38}{45}\right)\)
c) C= \(\left(\frac{-5}{9}\right).\frac{3}{11}+\left(\frac{-13}{18}\right).\frac{3}{11}\)
d) D= \(\left(2\frac{2}{15}.\frac{9}{17}.\frac{3}{32}\right):\left(\frac{-3}{27}\right)\)
Tính giá trị các biểu thức sau:
a, A = \(\left(3\dfrac{5}{6}-1\dfrac{1}{3}\right)\left(3\dfrac{4}{15}-2\dfrac{3}{5}\right)\)
b, B= \(\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\) c, C = \(\left(1-\dfrac{1}{3}\right)\left(1-\dfrac{1}{6}\right)\left(1-\dfrac{1}{10}\right)\left(1-\dfrac{1}{15}\right)...\left(1-\dfrac{1}{210}\right)\)
\(a,A=\left(3\dfrac{5}{6}-1\dfrac{1}{3}\right)\left(3\dfrac{4}{15}-2\dfrac{3}{5}\right)\)
\(\Leftrightarrow A=\left(3+\dfrac{5}{6}-1+\dfrac{1}{3}\right)\left(3+\dfrac{4}{15}-2+\dfrac{3}{5}\right)\)
\(\Leftrightarrow A=\left[\left(3-1\right)+\left(\dfrac{5}{6}+\dfrac{1}{3}\right)\right]+\left[\left(3-2\right)+\left(\dfrac{4}{15}+\dfrac{3}{5}\right)\right]\)
\(\Leftrightarrow A=\left[2+\left(\dfrac{5}{6}+\dfrac{2}{6}\right)\right]+\left[1+\left(\dfrac{4}{15}+\dfrac{9}{15}\right)\right]\)
\(\Leftrightarrow A=\left(2+\dfrac{7}{6}\right)+\left(1+\dfrac{13}{15}\right)\)
\(\Leftrightarrow A=\left(2+1+\dfrac{1}{6}\right)+\left(1+\dfrac{13}{15}\right)\)
\(\Leftrightarrow A=3\dfrac{1}{6}+1\dfrac{13}{15}\)
Vậy...
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\(b,B=\dfrac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)
\(\Leftrightarrow B=\dfrac{\left(2^2\right)^6.\left(3^2\right)^5+\left(2.3\right)^9.\left(2^3.3.5\right)}{\left(2^3\right)^4.3^{12}-\left(2.3\right)^{11}}\)
\(\Leftrightarrow B=\dfrac{2^{12}.3^{10}+2^9.3^9.2^3.3.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)
\(\Leftrightarrow B=\dfrac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{12}.3^{12}-2^{11}.3^{11}}\)
\(\Leftrightarrow B=\dfrac{\left(2^{10}.3^{10}\right)\left(1+5\right)}{\left(2^{11}.3^{11}\right)\left(2.3-1\right)}\)
\(\Leftrightarrow B=\dfrac{6}{\left(2.3\right).5}\)
\(\Leftrightarrow B=\dfrac{6}{6.5}\)
\(\Leftrightarrow B=\dfrac{1}{5}\)
Vậy....
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