Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a: A(x)+B(x)
\(=2x^3+3x^3+x^2-3x+3+5x^3+x^2+6x-2x-11\)
\(=10x^3+2x^2+x-8\)
b: A(x)-B(x)
\(=2x^3+3x^3+x^2-3x+3-5x^3-x^2-6x+2x+11\)
\(=-7x+14\)
c: Đặt C(x)=A(x)+B(x)
=>\(C\left(x\right)=10x^3+2x^2+x-8\)
\(C\left(1\right)=10\cdot1^3+2\cdot1^2+1-8=10+2+1-8=5\)>0
=>x=1 không là nghiệm của C(x)
a: \(\dfrac{-3}{8}+\dfrac{12}{25}-\dfrac{5}{8}+\dfrac{2}{-5}+\dfrac{13}{25}\)
\(=\left(-\dfrac{3}{8}-\dfrac{5}{8}\right)+\left(\dfrac{12}{25}+\dfrac{13}{25}\right)-\dfrac{2}{5}\)
\(=-1+1-\dfrac{2}{5}=-\dfrac{2}{5}\)
b: \(\dfrac{3}{7}\cdot\dfrac{20}{11}+\dfrac{9}{11}\cdot\dfrac{-3}{7}-2\dfrac{3}{7}\)
\(=\dfrac{3}{7}\left(\dfrac{20}{11}-\dfrac{9}{11}\right)-2-\dfrac{3}{7}\)
\(=\dfrac{3}{7}-2-\dfrac{3}{7}=-2\)
c: \(\dfrac{3}{2}+\dfrac{5}{4}-\dfrac{14}{16}\)
\(=\dfrac{12}{8}+\dfrac{10}{8}-\dfrac{7}{8}\)
\(=\dfrac{12+10-7}{8}=\dfrac{15}{8}\)
d: Sửa đề: \(\dfrac{2}{5}\cdot\dfrac{1}{3}-\dfrac{1}{15}:\dfrac{1}{5}\)
\(=\dfrac{2}{15}-\dfrac{1}{15}\cdot5\)
\(=\dfrac{2}{15}-\dfrac{1}{3}=\dfrac{2}{15}-\dfrac{5}{15}=-\dfrac{3}{15}=-\dfrac{1}{5}\)
e: \(\dfrac{15}{7}\cdot\dfrac{1}{3}+\dfrac{12}{7}\cdot\dfrac{2}{3}\)
\(=\dfrac{15}{21}+\dfrac{24}{21}\)
\(=\dfrac{39}{21}=\dfrac{13}{7}\)
f: \(32,8+4,2+\left(-4,3\right)+\left(-32,8\right)+4,3\)
\(=\left(32,8-32,8\right)+\left(4,2\right)+\left(-4,3+4,3\right)\)
=0+4,2+0
=4,2
(- \(\dfrac{2}{5}\))2 + \(\dfrac{1}{2}\) x (4,5 - 2) - 25%
= \(\dfrac{4}{25}\) + \(\dfrac{1}{2}\) x 2,5 - 0,25
= 0,16 + 1,25 - 0,25
= 0,16 + (1,25 - 0,25)
= 0,16 + 1
= 1,16
a; \(x+3,4\) = 15,8 x 6,2
\(x+3,4\) = 97,96
\(x\) = 97,96 - 3,4
\(x\) = 94,56
b; \(x\) x 3,5 = 54,6 : 5
\(x\) x 3,5 = 10,92
\(x\) = 10,92 : 3,5
\(x\) = 3,12
c; 2,5 : \(x\) = 22,2 - 2,2
2,5: \(x\) = 20
\(x\) = 2,5 : 20
\(x\) = 0,125
d; \(x\) - 3,24 = 567,8
\(x\) = 567,8 + 3,24
\(x\) = 571,04