TÍNH
\(\frac{12^3+3.12^2+3^3}{162}\)
\(\left(\frac{-10}{3}\right)^5.\left(\frac{-6}{5}\right)^4\)
\(\frac{7^5.5^7}{35^7}\)
\(\frac{12^3+3.12^2+3^{^3}}{162}\)
\(\left(-\frac{10}{3}\right)^5.\left(-\frac{6}{5}\right)^4\)
\(=\frac{-2^5.5^5}{3^5}.\frac{2^4.3^4}{5^4}\)
\(=\frac{-2^9.5}{3}=-\frac{2560}{3}\)
Tính
\(\frac{16}{2^{^x}}=2\)
\(\frac{\left(-3\right)^x}{81}=-27\)
\(8^x:2^{10}\)
\(\left(\frac{2^2}{4^2}.\frac{2^3}{16}\right)^{15}:\left(\frac{2^6}{16^2}\right)^{10}\)
\(\frac{12^3+3.12^2+3^3}{162}\)
Giúp mk vs huhuhu ToT
16/2^x = 2
=> 2^x . 2 = 16
2^x = 8
2^3 = 2^3
=> x = 3
\(\frac{16}{2^x}=2\Rightarrow16:2^x=2\)
\(\Rightarrow2^x=16:2=8\Rightarrow2^x=2^3\Rightarrow x=3\)
\(\frac{\left(-3\right)^x}{81}=-27\Rightarrow\left(-3\right)^x:81=-27\)
\(\Rightarrow\left(-3\right)^x=-27\cdot81=-2187\Rightarrow\left(-3\right)^x=\left(-3\right)^7\Rightarrow x=7\)
mk biết mỗi thế thôi. mong bạn thông cảm.
~CÁC BẠN GIÚP MK LÊN 200 ĐIỂM NHA. BẠN NÀO GIÚP THÌ MK K LẠI NHÉ.~
~THANKS~
a,\(\frac{16}{2^x}=2\)
\(\frac{2^4}{2^x}\)\(=2\)
\(2^{4-x}=2\)
\(4-x=1\)
x=3
b, \(\frac{\left(-3\right)^x}{\left(-3\right)^4}=\left(-3\right)^3\)
\(\left(-3\right)^x=\left(-3\right)^3\)
x-4=3
x=7
c,\(8^x:2^x=4\)
\(4^x=4\)
x=1
a)5.4 mũ 2-18 : 3 mũ 2
b)3 mũ 3 . 18- 3 mũ 3.12
c)80-(130-(12-4)mũ 2)
tính hợp lí
4.24.5^2-(3^3.18+3^3.12)
tính nhanh nha các bạn
4 . 24 . 5 ^ 2 - ( 3 ^ 3 . 18 + 3 ^ 3 . 12 )
= 4 . 24 . 25 - ( 9 . 18 + 9 . 12 )
= ( 4 . 25 ) . 24 - 9 . ( 18 + 12 )
= 100 . 24 - 9 . 30
= 2400 - 270
= 2130
\(4.24.5^2-\left(3^3.18+3^3.12\right)\)
=\(24.100-3^3\left(18+12\right)\)
=\(24000-270=23730\)
1
Thuc hien phep tinh
5.4^2 -18:3^2
3^3.18-3^3.12
39.213+87.39
80-[130-(12-4^2)]
5.4^2 -18:3^2
=5.16 -18:9
=80-2
=78
3^3.18-3^3.12
=27.18-27.12
=27.(18-12)
=27.6
=162
39.213+87.39
=39.(213+87)
=39.300
=11700
80-[130-(12-4^2)]
=80-[130-(12-16)]
=80-[130-(-4)]
=80-134
=-54
Thực hiện phép tính :
a) \(5.4^2-18:3^2\)
b) \(3^3.18-3^3.12\)
c) \(39.213+87.39\)
d) \(80-\left[130-\left(12-4\right)^2\right]\)
a) 5 . 42 – 18 : 32 = 5 . 16 - 18 : 9 = 80 - 2 = 78;
b) 33 . 18 – 33 . 12 = 27 . 18 - 27 . 12 = 486 - 324 = 162;
Lưu ý. Có thể áp dụng tính chất phân phối của phép nhân đối với phép cộng:
33 . 18 – 33 . 12 = 33 (18 - 12) = 27 . 6 = 162;
c) 39 . 213 + 87 . 39 = 39 . (213 + 87) = 39 . 300 = 11700;
d) 80 – [130 – (12 – 4)2] = 80 - (130 - 64) = 80 - 66 = 14.
Thực hiện phép tính:
a)\(\frac{10+2\sqrt{10}}{\sqrt{5}+\sqrt{2}}+\frac{8}{1-\sqrt{5}}\)
b) \(\frac{2\sqrt{8}-\sqrt{12}}{\sqrt{18}-\sqrt{48}}-\frac{\sqrt{5}+\sqrt{27}}{\sqrt{30}+\sqrt{162}}\)
c) \(\sqrt{\frac{2-\sqrt{3}}{2+\sqrt{3}}}+\sqrt{\frac{2+\sqrt{3}}{2-\sqrt{3}}}\)
d)\(\frac{\left(\sqrt{5}+2\right)^2-8\sqrt{5}}{2\sqrt{5}-4}\)
a) \(\frac{10+2\sqrt{10}}{\sqrt{5}+\sqrt{2}}+\frac{8}{1-\sqrt{5}}\)
= \(\frac{\left(10+2\sqrt{10}\right)\left(1-\sqrt{5}\right)}{\left(\sqrt{5}+\sqrt{2}\right)\left(1-\sqrt{5}\right)}+\frac{8\left(\sqrt{5}+\sqrt{2}\right)}{\left(1-\sqrt{5}\right)\left(\sqrt{5}+\sqrt{2}\right)}\)
= \(\frac{\left(10+2\sqrt{10}\right)\left(1-\sqrt{5}\right)+8\left(\sqrt{5}+\sqrt{2}\right)}{\left(1-\sqrt{5}\right)\left(\sqrt{5}+\sqrt{2}\right)}\)
= \(\frac{10-2\sqrt{5}+2\sqrt{10}-2\sqrt{2}}{\sqrt{5}+\sqrt{2}-5-\sqrt{10}}\)
= \(\frac{2\left(5-\sqrt{5}+\sqrt{10}-\sqrt{2}\right)}{\sqrt{5}+\sqrt{2}-5-\sqrt{10}}\)
= -2
b); c); d) làm tương tự
a,\(\frac{8^2+3^8+6^8}{4^3.9^4+6^3.12^5}\)
b,\(\frac{2^9.4^{10}}{8^8}\)
b) \(\frac{2^9.4^{10}}{8^8}=\frac{2^9.\left(2^2\right)^{10}}{\left(2^3\right)^8}=\frac{2^9.2^{20}}{2^{24}}=\frac{2^{29}}{2^{24}}=2^5=32.\)
Chúc bạn học tốt!
1) \(3^{x-1}-5.3^{x-1}=162\)
2) \(\frac{1+2y}{18}=\frac{1+4y}{24}=\frac{1+6y}{6x}\)
3) \(2^{x+1}.3^4=12^x\)
1, \(3^{x-1}-5.3^{x-1}=162\Rightarrow-4.3^{x-1}=162\)vì \(-4.3^{x-1}
3, \(2^{x+1}.3^4=12^x\Rightarrow2^x.2.3^4=12^x\Rightarrow2.3^4=12^x:2^x=6^x\Rightarrow2^x.3^x=2.3^4\Rightarrow\begin{cases}x=1\\x=3\end{cases}\) (vô lí) pt vô nghiệm
2, ta có \(\begin{cases}\frac{1+2y}{18}=\frac{1+6y}{6x}\\\frac{1+4y}{24}=\frac{1+6y}{6x}\end{cases}\) giải hệ pt ta tìm đc x và y