trả lời đi cần gấp

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

Thanks

Xx3,7=17,75

suy ra: Xx3,7x2=17,75x2

suy ra:Xx7,4=35,5(kết quả cần tìm)

\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}....\frac{15}{32}=\frac{1}{2}.\frac{1}{2}.\frac{1}{2}.\frac{2}{3}.\frac{1}{2}.\frac{3}{4}....\frac{1}{2}.\frac{15}{16}\)

\(=\left(\frac{1}{2}.\frac{1}{2}.....\frac{1}{2}\right).\left(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}....\frac{15}{16}\right)\)

Số số \(\frac{1}{2}\)là (15-1):1+1=15 số

Do đó \(\left(\frac{1}{2}.\frac{1}{2}.....\frac{1}{2}\right).\left(\frac{1}{2}.\frac{2}{3}.\frac{3}{4}....\frac{15}{16}\right)=\left(\frac{1}{2}\right)^{15}.\frac{1.2.3....15}{2.3.4....15.16}\)

\(=\frac{1}{2^{15}}.\frac{1}{16}=\frac{1}{2^{15}}.\frac{1}{2^4}=\frac{1}{2^{15+4}}=\frac{1}{2^{19}}\)

\(\Rightarrow2^x=\frac{1}{2^{19}}\)

\(\Rightarrow x=-19\)

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

4x3 đấy ko phải nhân đâu

\(4x^3+15=47\)

\(\Leftrightarrow4x^3=32\)

\(\Leftrightarrow x^3=8\)

\(\Leftrightarrow x^3=2^3\)

\(\Leftrightarrow x=2\)

\(4.2^x-3=125\)

\(\Leftrightarrow4.2^x=128\)

\(\Leftrightarrow2^x=32\)

\(\Leftrightarrow2^x=2^5\)

\(\Leftrightarrow x=5\)

ok thanks

a) 4x³+15=47

=> 4x³=47-15

=> 4x³=32

=> x³=32:4

=> x³=2³

=> x=2

b) 4.2^x-3=125

=> 4.2^x=125+3

=> 2^x=128:4

=> 2^x=32

=> 2^x=2⁵

=> x=5

4x³ + 15 = 47

4x³ = 47 - 15

4x³ = 32

x³ = 32 : 4

x³ = 8

x³ = 2³

x = 2

b) 4 . 2^x - 3 = 125

4 . 2^x = 125 + 3

4 . 2^x = 128

2^x = 128 : 4

2^x = 32

2^x = 2⁵

x = 5

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 ) \(4x^3+15=47\)

\(\Leftrightarrow4x^3=32\)

\(\Leftrightarrow x^3=8\)

\(\Leftrightarrow x^3=2^3\)

\(\Leftrightarrow x=3\)

\(4.2^x-3=125\)

\(\Leftrightarrow4.2^x=128\)

\(\Leftrightarrow2^x=32\)

\(\Leftrightarrow2^x=2^5\)

\(\Leftrightarrow x=5\)