a) \(4^x\)=64
b) 35⋮ x
c) 135- ( x-5)= 105:3
d) x ⋮ 25 và x <100
Tìm x ,biết A,2.x(x+1)-135=-200 B,4.x-5.(x-1)+15=13 C,2/3.x-1/4=3/5-7/8 D,1/2.(2.x-3)+105/2=-137/2
a: 2x(x+1)-135=-200
=>2(x^2+x)=-65
=>2x^2+2x+65=0
=>x^2+x+32,5=0
=>x^2+x+0,25+32,25=0
=>(x+0,5)^2+32,25=0(vô lý)
b: 4x-5(x-1)+15=13
=>4x-5x+5=-2
=>5-x=-2
=>x=5+2=7
c: 2/3x-1/4=3/5-7/8
=>2/3x=3/5-7/8+1/4=24/40-35/40+10/40=-1/40
=>x=-1/40:2/3=-1/40*3/2=-3/80
d: 1/2(2x-3)+105/2=-137/2
=>1/2(2x-3)=-137/2-105/2=-242/2=-121
=>2x-3=-242
=>2x=-239
=>x=-239/2
Tìm x:
a/ 2130-(x+130)+72=-64
b/135-|9-x|=35
c/10-|x+3|=-4-(-10)
a/ 2130-(x+130)+72=-64
\(2130-\left(x+130\right)=-64-72\) \(2130-\left(x+130\right)=-136\)\(x+130=2130+136\)\(x+130=2266\)\(x=2266-130\)\(x=2136\)vậy x=2136
a/ 2130-(x+130)+72=-64
<=> -x-130+72+2130=-64
<=> x=2130+72-130+64=2136
b/135-|9-x|=35
<=> |9-x|=135-35=100
<=> \(\left[\begin{array}{nghiempt}9-x=100\\9-x=-100\end{array}\right.\)
<=>\(\left[\begin{array}{nghiempt}x=-91\\x=109\end{array}\right.\)
c/10-|x+3|=-4-(-10)
<=> |x+3|=10+4+(-10)
<=>|x+3|=4
<=>\(\left[\begin{array}{nghiempt}x+3=4\\x+3=-4\end{array}\right.\)
<=>\(\left[\begin{array}{nghiempt}x=1\\x=-7\end{array}\right.\)
c/10-|x+3|=-4-(-10)
Tính nhanh:
a) 64 x 25 + 35 x 25 + 25
b) 58 x 42 + 32 x 8 + 5 x 16
c) ( 42 x 43 + 57 x 43 + 43 ) - 360 : 4
d) 456 : 2 x 181456 : 3 - 102
* Nhanh lên nhé *
a. 64 x 25 + 35 x 25 + 25
= 64 x 25 + 35 x 25 + 25 x 1
= 25 x ( 64 + 35 + 1 )
= 25 x 100
= 2500
b. 58 x 42 + 32 x 8 + 5 x 16
c. ( 42 x 43 + 57 x 43 + 43 ) - 360 : 4
= 42 x 43 + 57 x 43 + 43 x 1 - 90
= 43 x ( 42 + 57 +1 ) - 90
= 43 x 100 - 90
= 4300 - 90
= 4210
d. 456 : 2 x 181456 : 3 - 102
Trả lời:
a,\(64\times25+35\times25+25\)
\(=25\times\left(64+35+1\right)\)
\(=25\times100\)
\(=2500\)
b,\(58\times42+32\times8+5\times16\)
\(=2436+256+80\)
\(=2772\)
c,\(\left(42\times43+57\times43+43\right)-360\div4\)
\(=43\times\left(42+57+1\right)-90\)
\(=43\times100-90\)
\(=4300-90\)
\(=4210\)
d,\(456\div2\times181456\div3-102\)
\(=228\div3\times181456-102\)
\(=76\times181456-102\)
\(=13790656-102\)
\(=13790554\)
a,64 x 25 + 35 x 25 +25
=25x(64+35+1)
=25x100
=250
b, 58 x 42 +32 x 8 +5 x 16
=2772
c,(42 x 43 +57 x 43+43 )-360:4
=43x(42+57+1) - 360 :4
= 43 x 100 -90
=4300-90
=4210
d,456:2 x 181456:3 -102
=228x181456:3-102
=13790656-102
=13790554
a) 135 - 5 (x + 4) = 35
b)25 + 3 (x - 8) = 106
a) 135 - 5 (x + 4) = 35
5(x+4)=135-35
5(x+4)=100
x+4=100:5
x+4=20
x=20-4
x=16
b)25 + 3 (x - 8) = 106
3 (x - 8)=106-25
3 (x - 8)=81
x-8=81:3
x-8=27
x=27+8
x=35
a,5(x+4)=135-35
5(x+4)=100
x+4=100:5
x+4=20
x=20-4
x=16
b,3(x-8)=106-25
3(x-8)=81
x-8=81:3
x-8=27
x=27+8
x=35
1/ Tính nhanh
a) ( - 4 ) x ( + 125 ) x ( - 25 ) x 6 x ( - 8 )
b) 122 x ( - 12345 ) + 12345 x ( - 78 )
c) 36 x ( - 9 ) + 9 x ( - 64 )
d) ( - 18 ) x ( 50 - 22 ) - 25 x ( 32 - 62 )
e) 1 - 2 + 3 - 4 + .... + 43 - 44 + 45
f) ( - 1 ) + 2 + ( - 3 ) + 4 + ( - 5 ) + 6 + ...... + ( - 99 ) + 100
g) 5 - 10 + 15 - 20 + 25 - .... + 105 - 110
giải gấp nha ! cảm ơn rất nhiều !
a, (-4) . (+125) . (-25) . 6 . (-8)
=[ (-4) . (-25) ] . [ (+125) . (-8) ] . 6
= 100 . (-1000) . 6
= -100 000 . 6
= -600 000
b, 122 . (-12345) + 12345 . (-78)
= 12345 . [ (-122) + (-78) ]
= 12345 . (-200)
= -2 469 000
c, 36 . (-9) + 9 . (-64)
= 9 . [ (-36) + (-64) ]
= 9 . (-100)
= -900
a. 135 - 5 x (x + 4)=35
b. 25 + 3 x (x - 8)=106
c. 3\(^2\) x (x + 4) - 5\(^2\)=5.2\(^2\)
\(135-5\cdot\left(x+4\right)=35\)
\(5\cdot\left(x+4\right)=135-35\)
\(5\cdot\left(x+4\right)=100\)
\(x+4=100:5\)
\(x+4=20\)
\(x=20-4\)
\(x=16\)
b) \(25+3\cdot\left(x-8\right)=106\)
\(3\cdot\left(x-8\right)=106-25\)
\(3\cdot\left(x-8\right)=81\)
\(x-8=81:3\)
\(x-8=27\)
\(x=27+8\)
\(x=35\)
c) \(3^2\cdot\left(x+4\right)-5^2=5\cdot2^2\)
\(9\cdot\left(x+4\right)-25=5\cdot4\)
\(9\cdot\left(x+4\right)-25=20\)
\(9\cdot\left(x+4\right)=20+25\)
\(9\cdot\left(x+4\right)=45\)
\(x+4=45:9\)
\(x+4=5\)
\(x=5-4\)
\(x=1\)
Chúc bạn học tốt!!!!!!!!!!!!!!!!!!!!
1/2×(2×x-3)+105/2=-137/2 A,-12×25-25×75-25×13 B,-50/7×49/10-35/2×-10/7+ -25/3× -9/5 C,-354+265-156+125 D,-74+40-50+16-35 E,-2/3×4/5+-4/5×4/3-0,125
1/2×(2×x-3)+105/2=-137/2
1/2×(2×x-3)=-137/2-105/2
1/2×(2×x-3)=-242/2
2×x-3=-242/2:1/2
2×x-3=-242
2.x=(-242)+3
2.x=239
x=239:2
x=239/2
A,-12×25-25×75-25×13
=[(-12)-75-13].25
=(-100).25
-2500
B,-50/7×49/10-35/2×-10/7+ -25/3× -9/5
=(-35)-(-25)+(-13)
=-23
C,-354+265-156+125
=[(-354)-156]+(265+125)
=(-510)+277
=-233
D,-74+40-50+16-35
=(-74)+40+(-50)+16+(-35)
=[(-74)+(-35)]+[40+(-50)+16]
=(-109)+26
=-83
E,-2/3×4/5+-4/5×4/3-0,125
=-2/3.4/5+4/5.(-4/3)-0,125
=4/5.[-2/3+(-4/3)]-0,125
=4/5.(-2)-0,125
=-8/5-0,125
=(-1,6)+(-0,125)
=-1,725
Tìm x thuộc { 5;6;25;135 } sao cho ( 20+35+x ) không thuộc 5 khi đó giá trị của x là A.5 B.6 C.25 D.135
A) x -(25-x)=x-15
B) x-8=-13-8
C) x-(-15)=5-(-19)
D) (x+35)=2x+15+(13-4)
E) 5-2x=15-(-9)-3x
G) x+135=3x-15
a/ x - ( 25 - x) = x - 15
=> x - 25 + x = x - 15
=> 2x - x = -15 + 25
=> x = 10
b/ x - 8 = -13 - 8
=> x = -13 - 8 + 8 = -13
c/ x - (-15) = 5 - (-19)
=> x + 15 = 5 + 19 => x = 5 + 19 - 15 = 9
d/ (x + 35) = 2x + 15 + (13 - 4)
=> x + 35 = 2x + 15 + 13 - 4
=> x - 2x = 15 + 13 - 4 - 35
=> -x = -11 => x = 11
e/ 5 - 2x = 15-(-9) - 3x
=> 5 - 2x = 15 + 9 - 3x
=> -2x + 3x = 15 + 9 - 5
=> x = 19
g/ x + 135 = 3x - 15
=> x - 3x = -15 - 135
=> -2x = -150
=> x = -150/ - 2 = 75