2^x=78-5-3+1
2^x=71
=>x(xấp xỉ)=6,15
Vậy............
2^x=78-5-3+1
2^x=71
=>x(xấp xỉ)=6,15
Vậy............
Bài 1:Tìm Giá trị nhỏ nhất
A=3(x+1)^2+5
B=2|x+y|+3x^2-10
C=12(x-y)^2 +x^2-6
D= -5/2^2+1
Bài 2:Tìm Giá trị lớn nhất
A=5-2x
B=3-(x+1)^2-3(x+2y)^2
C=-12-3|x+1|-2(y-1)^2
D=5/2x^2-3
F=-5/3-2x^2
Tìm tất cả các cặp số nguyên (x,y) biết rằng a, (x + 3).(y - 2) = 7 b, (x + 1).(xy+2) = 5
Tìm x biết :a, 2/3 (x-1/4)=1/3(2x-1)
b,1/5*2^x+1/3*2^x+1=1/5*2^7+1/2*2^8
Bài 13: Tìm x:
1/ (2x – 15) + 17 = 6
2/ 15 – (4 – 3x) = - 4
3/ - 21 + 3(-x + 7) = -18
4/ 78 : (3x – 2) = -3
5/ -35 : 5.(-3 – 2x) = 35
tìm xy biết x-1/5 = -2/3 +-3/4
\(\text{Tìm x, biết:}\)
\(a\)) \(x-\dfrac{2}{3.5}-\dfrac{2}{5.7}-\dfrac{2}{7.9}-\dfrac{2}{9.11}-\dfrac{2}{11.13}-\dfrac{2}{13.15}=\dfrac{2}{5}\)
\(b\)) \(\dfrac{1}{2.3}.x+\dfrac{1}{3.4}.x+\dfrac{1}{4.5}.x+...+\dfrac{1}{49.50}.x=1\)
\(c\)) \(x-\dfrac{20}{11.3}-\dfrac{20}{13.15}-...-\dfrac{53}{55}=\dfrac{3}{11}\)
\(d\)) \(x+\dfrac{4}{5.9}+\dfrac{4}{9.13}+...+\dfrac{4}{41.45}=\dfrac{-37}{45}\)
\(e\)) \(\left(\dfrac{11}{12}.\dfrac{11}{2.23}.\dfrac{11}{23.34}...\dfrac{11}{89.100}\right).x=\dfrac{5}{3}\)
\(f\)) \(\left(\dfrac{2}{11.13}.\dfrac{2}{13.15}.\dfrac{2}{15.17}...\dfrac{2}{19.21}\right)-x+4+\dfrac{221}{231}=\dfrac{7}{3}\)
Tìm x để sau số nguyên: A=2/x B=3/1-x C=5/2x+7 D=x+2/x+1 E=x+4/x-1 G=2(x+3)/2x -1 H=11x -15/x+2 I=9x -1/3x-2 Mình đang cần gấp!!!!!!!
1) Tìm x biết
a) -3/7=x/91
B) x/5=6/-10
C) 2/x=x/8
d) x+1/3=-2/5
e)x -1/5=-2/7
f)-3/8-x=-2/5
g) x:8/11=11/3
h) -1/4.x=5/8.2/3