3/4.5/2.7/6
E = 2.3+3.4+4.5+3.6+2.7+4.15
F = 3. ( 12+13+14+15)+3(8+7+6+5)
mọi người giải giúp e vs ạ e đang cần gấp
cảm ơn mn
\(E=2.3+3.4+4.5+3.6+2.7+4.15=2\left(3+7\right)+3\left(4+6\right)+4\left(5+15\right)=2.10+3.10+4.20=20+30+80=130\)
\(F=3\left(12+13+14+15\right)+3\left(8+7+6+5\right)=3\left(12+8+13+7+14+6+15+5\right)=3\left(20+20+20+20\right)=3.80=240\)
f: Ta có: \(E=3\cdot\left(12+13+14+15\right)+3\left(8+7+6+5\right)\)
\(=3\left(12+13+14+15+8+7+6+5\right)\)
\(=3\cdot80=240\)
\(\dfrac{2^4.5^2.7}{2^3.5.7^2.11}\);\(\dfrac{2^3.3^3.5^3.7.8}{3.2^4.5^3.14}\)
\(\dfrac{4^2.5.11}{44.20}\);\(\dfrac{13.15.16}{18.65.7};\dfrac{7.2.8.5^2}{14.2.5}\)
\(\dfrac{2^3.3^3.5}{3.2^3.5^3}\)
a) \(\dfrac{2^4\cdot5^2\cdot7}{2^3\cdot5\cdot7^2\cdot11}=\dfrac{2^3\cdot5\cdot10\cdot7}{2^3\cdot5\cdot7\cdot77}=\dfrac{10}{77}\)
\(\dfrac{2^3\cdot3^3\cdot5^3\cdot7\cdot8}{3\cdot2^4\cdot5^3\cdot14}=\dfrac{2^3\cdot3\cdot5^3\cdot7\cdot3^2\cdot8}{3\cdot2^3\cdot2\cdot5^3\cdot14}=\dfrac{7\cdot3^2\cdot8}{2\cdot14}=\dfrac{63\cdot8}{2\cdot14}=18=\dfrac{1386}{77}\)
7^2x+1 - 2.7^4 = 7^4.5
\(7^{2x+1}-2.7^4=7^4.5\)
\(\Rightarrow7^{2x+1}=7^4.5+2.7^4\)
\(\Rightarrow7^{2x+1}=7^4.\left(5+2\right)\)
\(\Rightarrow7^{2x+1}=7^4.7\)
\(\Rightarrow7^{2x+1}=7^5\)
\(\Rightarrow2x+1=5\)
\(\Rightarrow2x=4\)
\(\Rightarrow x=2\)
a) 2^3.3^4/2^2.3^2.5 ; 2^4.5^2.11^2.7/2^3.5^3.7^2.11
Ta có:
\(\frac{2^3.3^4}{2^2.3^2.5}=\frac{2.3^2}{5}=\frac{18}{5}\)
\(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}=\frac{2.11}{5.7}=\frac{22}{35}\)
123-5.(x+4)=38
(3.x-2^4).7^3=2.7^4
6^2:4.3+2.5^2
5.4^2-18:3^2
80-(4.5^2-3.2^3)
23.75+25.23+180
2448:[119-(23-6)]
Tim so nhien x biet
(2600+6400)-3.x=1200
[(6.x-72):2-84].28=562
123-5.(x+4)=38
5.(x+4)=123-38
5.(x+4)=85
x+4=85:5
x+4=17
x=17-4
x=13
(3.x-2^4).7^3=2.7^4
(3.x-16).343=2.2401
(3.x-16).343=4802
3.x-16=4802:343
3.x-16=14
3.x=14+16
3.x=30
x=30:3
x=10
6^2:4.3+2.5^2
=36:4.3+2.25
=9.3+2.25
=27+50
=77
5.4^2-18:3^2
=5.16-18:9
=80-2
=78
80-(4.5^2-3.2^3)
=80-(4.25-3.8)
=80-(100-24)
=80-76
=4
23.75+25.23+180
=23.(75+25)+180
=23.100+180
=2300+180
=2480
2448:[119-(23-6)]
=2448:(119-17)
=2448:102
=24
(2600+6400)-3.x=1200
9000-3.x=1200
3.x=9000-1200
3.x=7800
x=7800:3
x=2600
[(6.x-72):2-84].28=562
(6.x-72):2-84=562:28
(6.x-72):2-84=281/14
(6.x-72):2=281/14+84
(6.x-72):2=1457/14
6.x-72=1457/14.2
6.x-72=1457/7
6.x=1457/7+72
6.x=1961/7
x=1961/7:6
x=1961/42
Tính nhanh
B= 3.4+4.5+5.5+....+19.20
C= 1.6+2.7+3.8+....+15.20
kyojpulgky-d90487906892489038
Rút gọn các phân số sau rồi quy đồng :
\(\frac{4.5+4.11}{8.7-4.3};\frac{-15.8+10.7}{5.6+20.3};\frac{2^4.5^2.7}{2^3.5.11.7^2}\)
phân số thứ nhất =16/11
phân số thứ hai = -5/9
phân số thứ ba = 10/77
Tìm x :
a,x*3.9+x*0.1=2.7
b.12.3/x-4.5/x=15
a ) \(x\times3,9+x\times0,1=2,7\)
\(x\times\left(3,9+0,1\right)=x\times4=2,7\)
x = 2,7 : 4 = 0,675
b ) \(\frac{12,3}{x}-\frac{4,5}{x}=15=\frac{7,8}{x}\)
\(=7,8\div x=15\)
\(x=15\div7,8=\frac{15}{7,8}\)
QUY ĐỒNG MẤU SỐ CÁC PHÂN SỐ Sau:a>
\(\frac{4.5+4.11}{8.7+4.3}\);\(\frac{15.8+10.7}{5.6+20.3}\)và \(\frac{2^4.5^2.7}{2^3.5.7^2.11}\)
b> \(\frac{-5^2-5.3^2}{5^3+5^2.3^2}\);\(\frac{4^6.9^5+6^9.120}{8^4.3^{12}-6^{11}}\)và\(\frac{2929-101}{2.1919+404}\)
Nhanh nha, ai trả lời vừa đúng, nhanh, dễ hiểu mk thisck cho