thuc hien phep tinh A=1/(a-b)(a-c)+1/(b-a)(b-c)+1/(c-a)(c-b)
\(\frac{1}{a\left(a-b\right)\left(a-c\right)}+\frac{1}{b\left(b-a\right)\left(b-c\right)}+\frac{1}{c\left(c-a\right)\left(c-b\right)}\) giup mik vs de bai la thuc hien phep tinh nhe
Thuc hien phep tinh 1 cach hop li
a, A = 120 - ( 61) × (-2)^3 × ( -1)^ 2n ( n thuoc N*)
b, B = 136 × (-47) +36 × 47 - (-1)^n (n le)
c, C = (-48) + 72 +36 + (-304)
a: A=120-61x(-8)
=120+488=608
b: =47(-136+36)-(-1)
=-4700+1=-4699
c: C=(-48-304+72)+36
=-352+72+36
=-280+36=-244
THUC HIEN CAC PHEP TINH
A)3.25-16:4
B)16.17-16.14
C)20-[30-(5-1) MŨ 2]
giải chi tiết hộ cái
Thuc hien phep tinh
A, 3/7 + 1/2 - (-3)/70
B, 3/5 + -1/25 - 35/100
C, 5/12 - 3/-16 + 3/4
D, 5/15 + 4/-12 + 1/7 - 1/-6
a,3/7 +1/2-[-3]/70
=13/14 -[-3]/70
=65/70 -[-3]/70
=34/35
b,3/5+-1/25 -35/100
=14/25 - 35/100
=56 /100 -35/100
= 21/100
c ,5/12 -3/-16+3/4
=29/48 +3/4
= 29/48 +36/48
=65/48
d, 5/15 +4/-12 +1/7 -1/-6
= 1/3 +1/-3 +1/7-1/-6
=0+1/7-1/-6
= 13/42
A.\(\dfrac{3}{7}+\dfrac{1}{2}+\dfrac{\left(-3\right)}{70}\)
=\([\dfrac{30}{70}+\dfrac{\left(-3\right)}{70}]\)+\(\dfrac{1}{2}\)
= \(\dfrac{27}{70}+\dfrac{35}{70}\)
=\(\dfrac{62}{70}=\dfrac{31}{35}\)
B.\(\dfrac{3}{5}+\dfrac{-1}{25}-\dfrac{35}{100}\)
=\(\dfrac{60}{100}+\dfrac{-4}{100}-\dfrac{35}{100}\)
=\(\dfrac{60+\left(-4\right)-35}{100}\)
=\(\dfrac{21}{100}\)
C.\(\dfrac{5}{12}-\dfrac{3}{-16}+\dfrac{3}{4}\)
=\(\left(\dfrac{5}{12}+\dfrac{9}{12}\right)-\dfrac{-3}{16}\)
=\(\dfrac{7}{6}-\dfrac{-3}{16}\)
=\(\dfrac{56}{48}-\dfrac{-9}{48}\)=\(\dfrac{65}{48}\)
D.\(\dfrac{5}{15}+\dfrac{4}{-12}+\dfrac{1}{7}-\dfrac{1}{-6}\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+(\dfrac{-2}{6}-\dfrac{-1}{6})\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{-1}{6}\)
=\((\dfrac{1}{3}+\dfrac{-1}{6})+\dfrac{1}{7}\)
=\(\dfrac{1}{6}+\dfrac{1}{7}\)=\(\dfrac{13}{42}\)
thuc hien phep tinh
a,1 va11/15 + 3 và 4/15 -1
b, 3/4 +1/2 -1/15
c, 6,25 +15,45-9,2
d, 3/4 : 1/2 x 8/9
phần a, là hỗn số nhé các bn
mk bt lam roi nhung cac bn cu lam di de mk xem ket qua co giong ko di mà
Thuc hien phep tinh 1 cach hop li
a, 120 - ( 61) × (-2)^3 × ( -1)^ 2n ( n thuoc N*)
b, 136 × (-47) +36 × 47
c, (-48) + 72 +36 + (-304)
b) \(=-47\left(136-36\right)\)
=\(-47.100=-4700\)
Thuc hien phep nhan vs da thuc:
a, (x2 + 2x+1)(x+1)
b, (x3-x2+2x-1)(5-x)
c, (x-5)(x3-x2+2x-1)
Giải:
a) \(\left(x^2+2x+1\right)\left(x+1\right)\)
\(=x^2.x+2x.x+1.x+x^2.1+2x.1+1.1\)
\(=x^3+2x^2+x+x^2+2x+1\)
\(=x^3+3x^2+3x+1\)
b) \(\left(x^3-x^2+2x-1\right)\left(5-x\right)\)
\(=x^3.5-x^2.5+2x.5-1.5+x^3.\left(-x\right)-x^2.\left(-x\right)+2x.\left(-x\right)-1.\left(-x\right)\)
\(=5x^3-5x^2+10x-5-x^4+x^3-2x^2+x\)
\(=6x^3-7x^2+11x-5-x^4\)
c) \(\left(x-5\right)\left(x^3-x^2+2x-1\right)\)
\(=x.x^3-5.x^3+x.\left(-x^2\right)-5.\left(-x^2\right)+x.2x-5.2x+x.\left(-1\right)-5.\left(-1\right)\)
\(=x^4-5x^3-x^3+5x^2+2x^2-10x-x+5\)
\(=x^4-6x^3+7x^2-11x+5\)
Chúc bạn học tốt!!!
lớp 8 Phạm Hoàng Giang không chơi kiểu lớp 7
đúng làm 8 mà làm
\(A=\left(x^2+2x+1\right)\left(x+1\right)=\left(x+1\right)^2\left(x+1\right)=\left(x+1\right)^3\)
\(A=x^3+3x^2+3x+1\)
thuc hien phep tinh
a, 516x2,15
b, 2,1655 : 5
c, 15/4 x 8/3 x 16/25 x 1/5
d, 3/7 : 5/4 x 3/5
a, 516 x 2,15 = 1109,4
b, 2,1655 : 5 = 0,4331
c, \(\frac{15}{4}\)x \(\frac{8}{3}\)x \(\frac{16}{25}\)x \(\frac{1}{5}\)
= 10 x \(\frac{16}{25}x\frac{1}{5}\)
= \(\frac{32}{5}x\frac{1}{5}\)
= \(\frac{32}{25}\)
d, \(\frac{3}{7}:\frac{5}{4}x\frac{3}{5}\)
= \(\frac{3}{7}x\frac{4}{5}x\frac{3}{5}\)
= \(\frac{12}{35}x\frac{3}{5}\)
= \(\frac{36}{175}\)
a, 516x2,15=1109,4
b, 2,1655 : 5=0,4331
c, 15/4 x 8/3 x 16/25 x 1/5
=10x16/25 x 1/5
=6,4x1/5
=1.28
d, 3/7 : 5/4 x 3/5=12/35x3/5=36/175
1..thuc hien phep tinh
a) [18-(-21)+(-9)]-13
b)125-139+200-(-75)
c) (-33)-(-12)-4
d) 22+(-31)-32+50
cậu lấy máy tính ra mà tính toán này của sách tập 1 số nguyên đúng không