Tìm x biết :
\(^{2^{50}\div2^x-5=11}\)
1. Tìm x, biết rằng:
a, ( x+3 )( x + 1) - x ( x - 5 ) = 11
b, ( 8x + 2 )( 1 - 3x ) + ( 6x - 1 )( 4x - 10 ) = -50
a) \(\left(x+3\right)\left(x+1\right)-x\left(x-5\right)=11\)
\(\Leftrightarrow x^2+x+3x+3-x^2+5x=11\)
\(\Leftrightarrow9x+3=11\)
\(\Leftrightarrow9x=11-3\)
\(\Leftrightarrow9x=8\)
\(\Leftrightarrow x=\dfrac{8}{9}\)
b) \(\left(8x+2\right)\left(1-3x\right)+\left(6x-1\right)\left(4x-10\right)=-50\)
\(\Leftrightarrow\left(8x-24x^2+2-6x\right)+\left(24x^2-60x-4x+10\right)=-50\)
\(\Leftrightarrow2x-24x^2+2+24x^2-64x+10=-50\)
\(\Leftrightarrow-62x+12=-50\)
\(\Leftrightarrow-62x=-50-12\)
\(\Leftrightarrow-62x=-62\)
\(\Leftrightarrow x=\dfrac{-62}{-62}\)
\(\Leftrightarrow x=1\)
a) \(\left(x+3\right)\left(x+1\right)-x\left(x-5\right)=11\)
\(x^2+x+3x+3-x^2+5x=11\)
\(x+8x+3=11\)
\(x+8x=8\)
\(x\left(8+1\right)=8\)
\(x=\dfrac{8}{9}\)
b) \(\left(8x+2\right)\left(1-3x\right)+\left(6x-1\right)\left(4x-10\right)=-50\)
\(8x-24x^2+2-6x+24x^2-60x-4x+10=-50\)
\(-62x+12=-50\)
\(-62x=-62\)
\(x=1\)
tìm x biết:
a/ 3/2*x-70/10/11:(131313/151515+131313/353535+131313/999999)=-5
b/ 0,25*x*(8/5:1/1/2+1/50)=7/50*(2,91+0,09)*4
c/ (2/11*13+2/13*15+...+2/19*21) *462-(0,04:(x + 1,05)):0,12=19
timf x, y, z biết
\(x\div y\div z=5\div3\div2\) và \(x^2-y^2+z^2=40\)
\(\frac{x}{5}=\frac{y}{3}=\frac{z}{2}\Rightarrow\frac{x^2}{25}=\frac{y^2}{9}=\frac{z^2}{4}\)
Áp dụng tính chất dãy tỉ số bằng nhau:
\(\frac{x^2}{25}=\frac{y^2}{9}=\frac{z^2}{4}=\frac{x^2-y^2+z^2}{25-9+4}=\frac{40}{20}=2\)
Suy ra:
x = 2 x 5 = 10
y = 2 x 3 = 6
z = 2 x 2 = 4
Tìm các số nguyên x biết:
a,(x-7)(x+3)<0
b,(x-50)(x-2)>0
c,(x+1)+(x+3)+(x+5)+...+(x+99)=0
d,(x-3)+(x-2)+(x-1)+...+10+11=11
cho mình tịch đi mình làm cho
bạn cho mình ba tích đi
tìm x
1, \(0,4\cdot x-\frac{1}{5}x=\frac{3}{4}\)
2, \(x\div1\frac{2}{7}=-3,5\)\
3, \(\left(\frac{2x}{5}-2\right)\div\left(-5\right)=\frac{3}{7}\)
4, x+ 20% x = -4,8
5, \(x-15\%x=-2\frac{11}{20}\)
6, \(\left(x\cdot25\%-\frac{2}{3}\right)\div2\frac{1}{3}=1\frac{5}{8}\)
1. 0,4x - 1/5x = 3/4
=> 1/5x = 3/4
=> x = 3/4 : 1/5
=> x = 15/4
2.
x : 1 2/7 = -3,5
=> x = -3,5 . 9/7
=> x = -9/2
3. ( 2x/5 - 2 ) : -5 = 3/7
=> 2x/5 - 2 = 3/7 . (-5)
=> 2x/5 - 2 = -15/7
=> 2x/5 = -15/7 + 2 = -1/7
=> 2x = -1/7 . 5 = -5/7
=> x = -5/7 : 2
=> x = -5/14
1 a) tìm tập hợp các số nguyên x biết
\(4\frac{5}{9}\div2\frac{5}{18}-7< x< \) \(\left(3\frac{1}{5}\div3,2+4,5\times1\frac{31}{45}\right)\)\(\div\left(-21\frac{1}{2}\right)\)
Tìm x:
a,\(15-\left(5-2x\right)=-4\)
b,\(\left|x-3\right|+1=4\)
c,\(5^x\cdot5^{x+1}\cdot5^{x+2}=10000000\div2^{18}\)
a.15-(5-2x)=-4
\(\Leftrightarrow\)15-5+2x=-4
\(\Leftrightarrow\)2x=-4-15+5
\(\Leftrightarrow\)2x=-14
\(\Leftrightarrow\)x=-7
b.TH1:x-3\(\ge\)0 \(\Rightarrow\)x\(\ge\)3
Ta có \(|\)x-3\(|\)=x-3
PT trên\(\Leftrightarrow\)x-3+1=4
\(\Leftrightarrow\)x=4+3-1
\(\Leftrightarrow\)x=6(nhận)
TH2:x-3<0\(\Leftrightarrow\)x<3
Ta có:\(|\)x-3\(|\)=-x+3
PT trên\(\Leftrightarrow\)-x+3+1=4
-x=4-3-1
x=0(nhận)
Vậy S={0;6}
chỗ 100000 là 1000000000000000000.mười tám chữ số 0
Tìm x 5/3×7 + 5/7×11 + 5/11×15 +...+5/x × (x+4) = 50/123
\(\Leftrightarrow\dfrac{5}{4}\left(\dfrac{4}{3\cdot7}+\dfrac{4}{7\cdot11}+...+\dfrac{4}{x\left(x+4\right)}\right)=\dfrac{50}{123}\)
=>(1/3-1/7+1/7-1/11+...+1/x-1/x+4)=50/123:5/4=50/123*4/5=40/123
=>1/3-1/x+4=40/123
=>1/x+4=1/123
=>x+4=123
=>x=119
250:2x-5=11
Tìm x
2^50:2^x-5=11
2^50:2^x=11+5
2^50:2^x=16
2^50:2^x=2^4
2^x=2^50:2^4
2^x=2^46
=>x=46
\(2^{50}:2^x-5=11\)
\(\Rightarrow2^{50}:2^x=16\)
\(\Rightarrow2^{50}:2^x=2^4\)
\(\Rightarrow2^x=2^{46}\Rightarrow x=46\)