17.75 - ( 0.5 x X : 2 - 4.2 ) = 15
tính bằng cách thuan tien :4.2 x 21 +8.4 x 15 +4.2 x48 +4,2
Tìm X :
30% x X + X x 0.5 + X + 3/4 X x = 15.3
Tính nhanh :
40 x 1.6+1.6 x 4.2 + 1600 x 0.018
AI LÀM NHANH VÀ ĐÚNG NHẤT SẼ CÓ 8 TICK NHA !
If X x 3.7 = 17.75 then 7.4 x X = ..........
X x 3.7 = 17.75
=> X = 17.75 : 3.7
=> X = 355/74
Then 7.4 x X = 7.4 x 355/74 = 35.5
Answer: 35.5
Xx3,7=17,75
suy ra: Xx3,7x2=17,75x2
suy ra:Xx7,4=35,5(kết quả cần tìm)
1/4.2/6.3/8...15/32=2^x. Tìm x
\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}....\frac{15}{32}=\frac{1}{2}.\frac{1}{2}.\frac{1}{2}.\frac{2}{3}.\frac{1}{2}.\frac{3}{4}....\frac{1}{2}.\frac{15}{16}\)
\(=\left(\frac{1}{2}.\frac{1}{2}.....\frac{1}{2}\right).\left(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}....\frac{15}{16}\right)\)
Số số \(\frac{1}{2}\)là (15-1):1+1=15 số
Do đó \(\left(\frac{1}{2}.\frac{1}{2}.....\frac{1}{2}\right).\left(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}....\frac{15}{16}\right)=\left(\frac{1}{2}\right)^{15}.\frac{1.2.3....15}{2.3.4....15.16}\)
\(=\frac{1}{2^{15}}.\frac{1}{16}=\frac{1}{2^{15}}.\frac{1}{2^4}=\frac{1}{2^{15+4}}=\frac{1}{2^{19}}\)
\(\Rightarrow2^x=\frac{1}{2^{19}}\)
\(\Rightarrow x=-19\)
Tìm X :
30% x X + X x 0.5 + X + 3/4 X x = 15.3
Tính nhanh :
40 x 1.6+1.6 x 4.2 + 1600 x 0.018
AI LÀM NHANH VÀ ĐÚNG NHẤT SẼ CÓ 8 TICK NHA !
30% x X + X x 0.5 + X + 3/4 x X =15.3
X x (30% + 0.5 + 1 +3/4) =15.3
X x 2.55=15.3
X=15.3 x 2.55
X =39.015
40 x 1.6 + 1.6 x 4.2 + 1600 x 0.018
=1.6 x (40+4.2) + 28.8
=1.6 x 44.2 +28.8
=99.52
nhớ k 8 cai nha
40*1.6+1.6*4.2+1600*0.018
=64+6.72+28.8
=70.72+28.8
=99.52
Tìm x,biết
a) 4 x3+15=47
b)4.2x -3 =125
4x^3 + 15=47
4.2^x - 3 = 125
tìm x nhe mấy bn
\(4x^3+15=47\)
\(\Leftrightarrow4x^3=32\)
\(\Leftrightarrow x^3=8\)
\(\Leftrightarrow x^3=2^3\)
\(\Leftrightarrow x=2\)
\(4.2^x-3=125\)
\(\Leftrightarrow4.2^x=128\)
\(\Leftrightarrow2^x=32\)
\(\Leftrightarrow2^x=2^5\)
\(\Leftrightarrow x=5\)
Tìm số tự nhiên x , biết:
a) 4x^3 + 15 = 47
b)4.2^x - 3 = 125
a) 4x3+15=47
=> 4x3=47-15
=> 4x3=32
=> x3=32:4
=> x3=23
=> x=2
b) 4.2x-3=125
=> 4.2x=125+3
=> 2x=128:4
=> 2x=32
=> 2x=25
=> x=5
4x3 + 15 = 47
4x3 = 47 - 15
4x3 = 32
x3 = 32 : 4
x3 = 8
x3 = 23
x = 2
b) 4 . 2x - 3 = 125
4 . 2x = 125 + 3
4 . 2x = 128
2x = 128 : 4
2x = 32
2x = 25
x = 5
Tìm số tự nhiên x , biết:
a) 4x^3 + 15 = 47
b)4.2^x - 3 = 125
a) \(4x^3+15=47\)
\(\Rightarrow4x^3=32\)
\(\Rightarrow x^3=8\)
\(\Rightarrow x^3=2^3\)
\(\Rightarrow x=2\)
Vậy \(x=2\)
b) \(4.2^x-3=125\)
\(\Rightarrow4.2^x=128\)
\(\Rightarrow2^x=32\)
\(\Rightarrow2^x=2^5\)
\(\Rightarrow x=5\)
Vậy \(x=5\)
a ) \(4x^3+15=47\)
\(\Leftrightarrow4x^3=32\)
\(\Leftrightarrow x^3=8\)
\(\Leftrightarrow x^3=2^3\)
\(\Leftrightarrow x=3\)
\(4.2^x-3=125\)
\(\Leftrightarrow4.2^x=128\)
\(\Leftrightarrow2^x=32\)
\(\Leftrightarrow2^x=2^5\)
\(\Leftrightarrow x=5\)