{7+X}x4+x=108
{7+X}X4+X=108
(7+X)x4+X=108
=> 28+4X+X=108
=> 5X=108-28
=> 5X =80
=> X=16
(7+X)x4+X=108 cách giải
Cho 3 đa thức: A(x)= -7+2x2+x4+3x5-x3
B(x)= -x+x4+2x3-7
C(x)= 2x-x4-3x3
Tính A(x)+B(x)-C(x)
\(A\left(x\right)+B\left(x\right)-C\left(x\right)\)
\(=\left(-7+2x^2+x^4+3x^5-x^3\right)+\left(-x+x^4+2x^3-7\right)-\left(2x-x^4-3x^3\right)\)
\(=3x^5+3x^4+4x^3+2x^2-3x-14\)
Cau 1:
Tim x, biet: 1-4+7-10+.............-x=-75
Cau 2:
Cho x1, x2, x3, x4, x5 thuộc Z
Biết x1+ x2 + x3 + x4 + x5=0
và x1 + x2=x3+ x4= x4 + x5 =2
Tinh x3, x4 , x5
Cau 3: Tim x biet
(x+7+1) chia het cho (x+7)
Tính f(x) – g(x) với:
f(x) = x7 – 3x2 – x5 + x4 – x2 + 2x – 7
g(x) = x – 2x2 + x4 – x5 – x7 – 4x2 – 1
Thu gọn, sắp xếp đa thức theo lũy thừa giảm của biến:
* Ta có: f(x) = x7 – 3x2 – x5 + x4 – x2 + 2x – 7
= x7 - (3x2+ x2) – x5+ x4 + 2x – 7
= x7 – 4x2 – x5+ x4 + 2x – 7
= x7 – x5 + x4 – 4x2 + 2x - 7
g(x) = x – 2x2 + x4 – x5 – x7 – 4x2 – 1
= x – ( 2x2 + 4x2) + x4 – x5 –x7 – 1
= x – 6x2 + x4 – x5 – x7 – 1
= -x7 – x5 + x4 – 6x2 + x – 1
* f(x) – g(x)
Vậy f(x) – g(x) = 2x7 + 2x2 + x - 6
X x 11/5+X X4/7=5/77
X x (\(\dfrac{11}{5}\)+ \(\dfrac{4}{7}\)) = \(\dfrac{5}{77}\)
X x \(\dfrac{97}{35}\)=\(\dfrac{5}{77}\)
X = \(\dfrac{5}{77}:\dfrac{97}{35}\)
X = \(\dfrac{25}{1067}\)
Xx[11/5+4/7]=5/77
Xx97/35=5/77
X=5/77:97/35
x=175/7569
108×x-7×x-x=201200
108×x-7×x-x=201200
x*(108-7-1)=201200
x*100=201200
x=201200:100
x=2012
VẬy x=2012
108 x X -7 x X - X = 201200
X x (108-7-1) = 201200
X x 100 =201200
X = 201200 : 100
X = 2012 ok
Tìm x :108×x-7×x-x=201200
Tìm x biết (7 + x) x 4 + x = 108
=>28+4x+x=108
=>5x=108-28
=>5x=80
=>x=80/5
=>x=16
16
tick nha nếu mún cách giải, bài này dễ thui mà
(7+x)x4+x=108
28+4x+x=108
28+5x=108
5x=80
x=16