thuc hien phep tinh sau:
-a^2(3a-5)+4a(a^2-a)
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a) 5+(-2)+(18-23)+2
=5+(18-23)+[(-2)+2]
=5+ (-5) + 0
= 0
b)|-6|:(-3)-43+(-2)2.11
=6:(-3)-43+4.11
= -2 -43+ 44
= -45 + 44
= -1
B = ( \(\dfrac{5}{7}.0,6:3\dfrac{1}{2}\)) . ( 40% - 1,4) . \(\left(-2\right)^3\)
= (\(\dfrac{5}{7}.\dfrac{3}{5}\): \(\dfrac{7}{2}\)) . ( \(\dfrac{2}{5}-\dfrac{7}{5}\)) . (-8)
= (\(\dfrac{15}{35}:\dfrac{7}{2}\)) . \(\dfrac{-5}{5}\) . ( -8)
= (\(\dfrac{3}{7}.\dfrac{2}{7}\)) . (-1) . (-8)
= \(\dfrac{6}{49}\) . (-1) . (-8)
= \(\dfrac{-6}{49}\) . (-8)
= \(\dfrac{48}{49}\)
Vậy: B =\(\dfrac{48}{49}\)
Nhớ tick nha
B=(\(\dfrac{3}{7}.\dfrac{2}{7}\)).(\(\dfrac{4}{10}-\dfrac{14}{10}\)).(-8)
B=\(\dfrac{3}{7}.\left(-1\right)\left(-8\right)\)
B=\(\dfrac{24}{7}\)
a ) \(\left(3x^2-4x+5\right)\left(2x^2-4\right)-2x\left(3x^3-4x^2+8\right)\)
\(=\left(3x^2-4x+5\right).2x^2-4\left(3x^2-4x+5\right)-6x^4+8x^3-16x\)
\(=6x^4-8x^3+10x^2-12x^2+16x-20-6x^4+8x^3-16x\)
\(=\left(6x^4-6x^4\right)+\left(8x^3-8x^3\right)-\left(12x^2-10x^2\right)+\left(16x-16x\right)-20\)
\(=-2x^2-20\)
b ) \(\left(1-3x+x^2\right)\left(2-4x\right)+2x\left(2x^2+5\right)\)
\(=2\left(1-3x+x^2\right)-4x\left(1-3x+x^2\right)+4x^3+10x\)
\(=2-6x+2x^2-4x+12x^2-4x^3+4x^3+10x\)
\(=\left(4x^3-4x^3\right)+\left(12x^2+2x^2\right)+\left(10x-6x-4x\right)+2\)
\(=14x^2+2\)
a)187 + [923 - (923 + 887)]
= 187 + [923 - 923 - 887]
= 187 + 923 - 923 - 887
= 187 + 0 - 887
= 187 - 887
= -700
b)39 . 187 + 302 - 78 . 39
= 39 . 187 + 900 - 78 . 39
= 39 . (187 - 78) + 900
= 39 . 109 + 900
= 4251 + 900
= 5151
a, 187+[923-(923+887)]
=187+[923-923-887]
=187-887
=-700
b, 39.187+302-78.39
=39.(187-78)+900
=39.109+900
=4251+900
=5151
Câu b bạn xem lại đầu bài là 78 hay 87 nha. Là 87 sẽ đúng hơn đó.
a: \(=205-\left[1200-\left(16-6\right)^3\right]:140\)
\(=205-\left[1200-10^3\right]:140\)
\(=205-\dfrac{200}{140}=205-\dfrac{10}{7}=\dfrac{1425}{7}\)
b: \(=\left[25-4\cdot3+9\cdot4+16\right]:5\)
\(=\left(25-12+36+16\right):5=\dfrac{65}{5}=13\)
a)
\(\left[\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right]:\frac{5}{6}+\frac{1}{2}\)
=\(\left[\frac{9}{24}+\frac{-18}{24}+\frac{14}{24}\right]:\frac{5}{6}+\frac{1}{2}\)
=\(\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)
=\(\frac{5}{24}.\frac{6}{5}+\frac{1}{2}\)
=\(\frac{1}{4}+\frac{1}{2}=\frac{1}{4}+\frac{2}{4}=\frac{3}{4}\)
tk ủng hộ mk nha ạ!!!!!!!!!!!!!
{[( 10 * 2 * 3 ) * 5 ] + 2 - 2 * 6 } + ( 4 * 5 ) ^ 2
= [ ( 60 * 5 ) + 2 - 12 ] + 20^2
= [ 300 + ( -10 )] + 400
= 290 + 400
= 690
Giải:
\(-a^2\left(3a-5\right)+4a\left(a^2-a\right)\)
\(=-3a^3+5a^2+4a^3-4a^2\)
\(=\left(-3a^3+4a^3\right)+\left(5a^2-4a^2\right)\)
\(=a^3+a^2\)
\(=a^2\left(a+1\right)\)
Vậy ...