\(5^{2x-3}-2\cdot5^2=5^2\cdot3\)
\(\Rightarrow5^{2x-3}-50=75\)
\(\Rightarrow5^{2x-3}=75+50\)
\(\Rightarrow5^{2x-3}=125\)
\(\Rightarrow5^{2x-3}=5^3\)
\(\Rightarrow2x-3=3\)
\(\Rightarrow2x=6\)
\(\Rightarrow x=\dfrac{6}{2}=3\)
\(5^{2x-3}-2\cdot5^2=5^2\cdot3\)
\(\Rightarrow5^{2x-3}-50=75\)
\(\Rightarrow5^{2x-3}=75+50\)
\(\Rightarrow5^{2x-3}=125\)
\(\Rightarrow5^{2x-3}=5^3\)
\(\Rightarrow2x-3=3\)
\(\Rightarrow2x=6\)
\(\Rightarrow x=\dfrac{6}{2}=3\)
Tìm số nguyên x , nếu biết
1. 7.4^x=7.4^3
2.3/2.5^x =3/2.5^12
3 . 2^x=2.2^8
4. 5.3^x=7.3^5-2.3^5
Chứng minh rằng
\(A=\dfrac{8}{1^2.3^2}+\dfrac{16}{3^2.5^2}+\dfrac{24}{5^2.7^2}+...+\dfrac{120}{29^2.31^2}< 1\)
CÂU 1:TÍNH
A, 2^2.5+149.7^2
B,3^2.3^5 /3^4
C, 4.(-1/2)^3 +1/2.5
D,(1+2/3-1/4):(1/2-2/3)^2
E,TRỊ TUYỆT ĐỐI NHA /-3-1/2/;21/4+3/4
Tính: \(H=\frac{8}{1^2.3^2}+\frac{16}{3^2.5^2}+\frac{24}{5^2.7^2}+...+\frac{48}{11^2.13^2}\)
a, Cho biểu thức \(P=2x+2xy-y\)
Tính giá trị của P với \(|x|=2.5\)và \(y=-0.75\)
b, Rút gọn biểu thức
\(Q=\frac{2^{12}.3^5-4^6.81}{\left(2^2.3\right)^6+8^4.3^5}\)
Tìm x
(3^2-2^3)x+3^2.2^2=4^2.3
x^5-x^3=0
(x-1)^2+(-3)^2=5^2.(-1)^100
(2x-1)^2-(2x-1)=0
2Tìm X:
a.(19x+2.5^2):14=(13-8)^2-4^2
b.2.3^x=10.3^12+8.27^4
c.{x^2-[6^2-(8^2-9.7)^3-7.5]^3-5.3}^3=1
d.60-3(x-2)=51
e.4x-20=2^5:2^2
Tìm x \(3^3.x^2-2^4.x^2=8^2.5-4^2.3^2\)
\(\left[\left(\dfrac{1}{2}\right)^2-\left(\dfrac{1}{3}\right)^3\right]x+3^2.2^2=4^2.3\)
tính:a.\(2^6.5^6\)b.\(8^2.5^2\)c.\(4^3.5^3\)d.\(5^2.6^2.3^2\)e.\(\frac{625^5}{25^8}\)g.\(\frac{3^9}{7}.\frac{7^9}{3}\)
giúp mình nha các bạn !