\(8^x:4^x=4\)
Giúp mình nha
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\Rightarrow\)x-8+x-4-x-1=0
\(\Rightarrow\)x-13=0
\(\Rightarrow\)x=13
học tốt nha
\(\left(x-8\right)+\left(x-4\right)=x+1\)
\(\Leftrightarrow x-8+x-4=x+1\)
\(\Leftrightarrow2x-12=x+1\)
\(\Leftrightarrow2x-x=12+1\Leftrightarrow x=13\)
Vậy \(x=13\)
\(\left(x+2\right)+\left(x+4\right)+...+\left(x+20\right)=160\)
\(x+2+x+4+...+x+20=160\)
\(\left(x+x+x+...+x\right)+\left(2+4+...+20\right)=160\)
\(x\cdot20+\frac{\left(20+2\right)\cdot\left(\left(20-2\right):2+1\right)}{2}=160\)
\(x\cdot20+110=160\)
\(x\cdot20=160-110\)
\(x\cdot20=50\)
\(x=50:20\)
\(x=2,5\)
Vậy \(x=2,5\)
[ x + 2 ] + [ x + 4 ] + [ x + 6 ] + ... + [ x + 20 ] = 160
( 20 + 2 ) x 10 : 2 + 10x = 160
22 x 10 : 2 + 10x = 160
220 : 2 + 10x = 160
110 + 10x = 160
10x = 160 - 110
10x = 50 ; x = 5
[ 1/2 + 1/4 + 1/8 + ... + 1.64 ] /x = 3/8
=> [ ( 1/2 + 1/4 ) + ( 1/8 + 1/16 ) + ( 1/32 + 1/64 ) ] / x = 3/8
[ 3/4 + 3/16 + 3/64 ] / x = 3/8
[ 48/64 + 12/64 + 3/64 ] / x = 3/8
=> 63/64x = 3/8
=> 64x = 21 x 8
64x = 168
x = 2,625
k chắc nha
=(8*125)*2019-(125*4)*2018
=1000*2019-1000*2018
=1000*(2019-2018)=1000*1=1000
8 x 2019 x125 - 250 x 2018 x 4
= ( 8x 125) - ( 250x 4)x 125
=1000-1000 x 125
0 x 125
= 0
mk chẳng bt đúng ko nữa
\(A=2\times4+4\times6+...+98\times100\)
\(A=2.2+2.12+...+2.149\)
\(A=2.\left(2+12+...+149\right)\)
Tự làm nốt( dấu x = dấu chấm )
\(a)\)\(\left[\left(8.x-12\right)\div4\right].3^3=3^6\)
\(\left[\left(8.x-12\right)\div4\right]=3^6\div3^3\)
\(\left[\left(8.x-12\right)\div4\right]=3^3\)
\(\left(8.x-12\right)\div4=27\)
\(\left(8.x-12\right)=27.4\)
\(8.x-12=108\)
\(8.x=108+12\)
\(8.x=120\)
\(x=120\div8\)
\(x=15\)
\(b)\)\(3^{2.x-4}-x^0=8\)
\(3^{2.x-4}-1=8\)
\(3^{2.x-4}=8+1\)
\(3^{2.x-4}=9\)
\(3^{2.x-4}=3^2\)
\(2.x-4=2\)
\(2.x=2+4\)
\(2.x=6\)
\(x=3\)
Tính nhanh:
36 x 28 + 4 x 9 x 82 + 64 x 69 + 8 x 41 x 8
= 36 x 28 + ( 4 x 9 ) x 82 + 64 x 69 + ( 8 x 8 ) x 41
= 36 x 28 + 36 x 82 + 64 x 69 + 64 x 41
= 36 x ( 28 + 82 ) + 64 x ( 69 + 41 )
= 36 x 110 + 64 x 110
= 110 x ( 36 + 64 )
= 110 x 100
= 11000
^^ Học tốt nhé!
\(\left(x+9\right)+\left(x-8\right)+\left(x+7\right)+\left(x-6\right)+\left(x+5\right)+\left(x-4\right)+\left(x+3\right)+\left(x-2\right)+\left(x+1\right)=95.9\\ =>x+9+x-8+x+7+x-6+x+5+x-4+x+3+x-2+x+1=855\\ =>\left(x+x+x+x+x+x+x+x+x\right)+\left(9-8+7-6+5-4+3-2+1\right)=855\\ =>9x+5=855\\ =>9x=855-5\\ =>9x=850\\ =>x=\dfrac{850}{9}\)
\(\left(x+9\right)+\left(x-8\right)+...+\left(x-2\right)+\left(x+1\right)\)
\(=x+9+x-8+...+x-2+x+1\)
\(=\left(x+9+x-8\right)+...+\left(x+5\right)+...+\left(x-2+x+1\right)\)
(Ta gộp 4 số vào 1 tổng, riêng (x+5) là ta giữ nguyên)
\(=\left(2x-1\right)+...+\left(x+5\right)+...+\left(2x-1\right)\)
\(=4\left(2x-1\right)+\left(x+5\right)\)
\(=8x-4+x-5\)
\(=9x-9\) (1)
Từ bài toán trên, ta có:
\(\left(x+9\right)+\left(x-8\right)+...+\left(x-2\right)+\left(x+1\right)=95,9\)
Từ (1)
\(\Leftrightarrow9x-9=95,9\)
\(9x=95,9-9\)
\(x=86,9:9\)
\(x=9,6\left(5\right)\)
x = 1
'-'
x = 4
'-'