( a x5 -14) + (a x 3 + 24) = 125
(X x5 - 19 ) + ( x x 3 -+24 ) = 125. Tìm x
\(\left(x\times5-19\right)+\left(x\times3-24\right)=125\)
\(x\times\left(5+3\right)-\left(19+24\right)=125\)
\(x\times8-43=125\)
\(x\times8=125-43\)
\(x\times8=82\)
\(x=\frac{82}{8}=\frac{41}{4}\)
Tìm số tự nhiên x, biết:
a, 2 x + 1 3 = 27
b, 2 x - 1 3 = 125
c, x + 1 4 = 2 x 4
d, 2 x - 1 5 = x 5
a) Ta có: 2 x + 1 3 = 3 3 nên 2x + l = 3. Do đó x = l.
b) Ta có: 2 x - 1 3 = 5 3 nên 2x - 1 = 5. Do đó x = 3.
c) Ta có: x + 1 4 = 2 x 4 nên x +1 = 2x. Do đó x = 1.
d) Ta có: 2 x - 1 5 = x 5 nên 2x - l = x. Do đó x = l
( X x5-19)+(Xx3+24)=125
X=
(x*5-19)+(x*3+24)=125.
x*5-19+x*3+24=125.
x*(5+3)+(24-19)=125.
=>x*8+5=125.
=>x*8=120( bớt cả 2 vế đi 5 đơn vị)
=>x=120:8.\
=>x=15.
Vậy x=15.
\(\left(x\cdot5-19\right)+\left(x\cdot3+24\right)=125\)
\(\Rightarrow5x-19+3x+24=125\)
\(\Rightarrow5x+3x=125+19-24\)
\(\Rightarrow8x=120\)
\(\Rightarrow x=120:8=15\)
Vậy x = 15
Tìm x để có các phân số bằng nhau :
a) 2/3=12/x
b) 24/36=x/12
c)14/56=1/x
d) x/125=2/5
\(a)\frac{2}{3}=\frac{12}{x}\)
\(\Rightarrow2\cdot x=12\cdot3\)
\(\Rightarrow2\cdot x=36\)
\(\Rightarrow x=36:2=18\)
Vậy x = 18
\(b)\frac{24}{36}=\frac{x}{12}\)
Rút gọn : \(\frac{24}{36}=\frac{24:12}{36:12}=\frac{2}{3}\)
\(\Rightarrow\frac{2}{3}=\frac{x}{12}\)
\(\Rightarrow2\cdot12=x\cdot3\)
\(\Rightarrow x=\frac{2\cdot12}{3}=8\)
Vậy x = 8
\(c)\frac{14}{56}=\frac{1}{x}\)
Rút gọn : \(\frac{14}{56}=\frac{14:14}{56:14}=\frac{1}{4}\)
\(\Rightarrow\frac{1}{4}=\frac{1}{x}\)
\(\Rightarrow x=4\)
Vậy x = 4
\(d)\frac{x}{125}=\frac{2}{5}\)
\(\Rightarrow x\cdot5=2\cdot125\)
\(\Rightarrow x\cdot5=250\)
\(\Rightarrow x=250:5=50\)
Vậy x = 50
tìm y biết :
a) (x + 125) : 312 = 14 (dư 300)
b) (x – 234) : 23 = 128 (dư 21)
c) (x - 24) x 2020 = 2020 x 33
d) 5 x (x + 2019) = 3800 x 5
a.(x + 125) : 312 = 14 (dư 300)
x+125 = 14 x 312 + 300
x+125 = 4 668
x= 4 668 - 125
x=4 543
b.(x-234):23=128 (dư 21)
x-234=128 x 23 + 21
x-234=2 965
x=2 965 + 234
x=3 199
c.(x-24) x 2020=2020x33
(x-24)x2020=66 660
x-24=66 660:2020
x-24=33
x=33+24
x=57
d.5 x (x+2019)=3800 x 5
5 x (x+2019)=19 000
x+2019=19000:5
x+2019=3800
x=3800-2019
x=1 781
HẾT=)))
tìm y biết :
a) (x + 125) : 312 = 14 (dư 300)
b) (x – 234) : 23 = 128 (dư 21)
c) (x - 24) x 2020 = 2020 x 33
d) 5 x (x + 2019) = 3800 x 5
a.(x + 125) : 312 = 14 (dư 300)
x+125 = 14 x 312 + 300
x+125 = 4 668
x= 4 668 - 125
x=4 543
b.(x-234):23=128 (dư 21)
x-234=128 x 23 + 21
x-234=2 965
x=2 965 + 234
x=3 199
c.(x-24) x 2020=2020x33
(x-24)x2020=66 660
x-24=66 660:2020
x-24=33
x=33+24
x=57
d.5 x (x+2019)=3800 x 5
5 x (x+2019)=19 000
x+2019=19000:5
x+2019=3800
x=3800-2019
x=1 781
HẾT=)))
Tính nhanh:
a) 15 x 18
b)25×24
c)125×72
d)55×14
Bài làm
a) 15 x 18
= 15 x 2 x 9
= 30 x 9
= 27
b) 25 × 24
= 25 x 4 x 6
= 100 x 6
= 600
c) 125 × 72
= 125 x 8 x 9
= 1000 x 9
= 9000
d) 55 × 14
= 5 x 11 x 2 x 7
= ( 5 x 2 ) x ( 11 x 7 )
= 10 x 77
= 770
# Học tốt #
15 x 18 = 270
25 x 24 = 600
125 x 72 = 9000
55 x 14 = 770
Bài làm
a) 15 x 18
= 15 x 2 x 9
= 30 x 9
= 270
b) 25 × 24
= 25 x 4 x 6
= 100 x 6
= 600
c) 125 × 72
= 125 x 8 x 9
= 1000 x 9
= 9000
d) 55 × 14
= 5 x 11 x 7 x 2
= ( 5 x 2 ) x ( 7 x 11 )
= 10 x 77
= 770
# Học tốt #
a) 25 . 8 - 12 . 5 + 272 : 17 - 8
b) 125 : 25 + 14 - 142 : 71
c) 13 . 17 - 256 : 16 + 14 :7 -1
d) 15 . 24 - 14 . 5 ( 145 : 5 - 27 )
2, Tìm X, biết:
a) 37 + x = 55
b) x - 31 = 24
c) 21 ( x - 11 ) = 21
d) 9 . ( x - 29 ) = 0
e) ( x - 1954 ) . 5 = 50
f) 30 . 60 - x = 30
1a) 25 .8 - 12.5 + 272 :17 - 8
= 200 - 60 + 16 - 8
= 140+16-8
= 156 - 8
= 148
b) 125: 25 +14 - 142 : 71
= 5 + 14 - 2
= 19 - 2 = 17
c) 13. 17 - 256: 16 + 14 : 7 - 1
= 221 - 16 + 2 - 1
= 205 + 2 - 1
= 207 - 1 = 206
d) 15 . 24 - 14 . 5 (145 : 5 - 27)
= 360 - 70 (29- 27)
= 360 - 70 . 2
= 360 - 140
= 220
2a) 37 + x = 55
x= 55 - 37
x = 18
b) x- 31 = 24
x = 24 + 31
x = 55
c) 21 (x-11) = 21
x - 11 = 21 : 21
x = 1 +11
x = 12
d ) 9. (x - 29)= 0
x - 29 = 0 :9
x = 29
e) (x - 1954) . 5 = 50
x - 1954 = 50 : 5
x = 1964
f ) 30 . 60 - x = 30
1800 - x = 30
x = 1800 - 30
x = 1770
Viết mỏi tay quá huhuh
a. \(\frac{x+109}{3}+\frac{x+125}{5}+\frac{x+149}{7}+\frac{x+181}{9}=24\)24
b. \(\frac{x-96}{2}+\frac{x-88}{4}+\frac{x-76}{6}+\frac{x-60}{8}=14\)
c. \(\frac{155x-24}{51}+\frac{185x-48}{57}+\frac{205x-3}{61}\)= 16