Sơ đồ thể hiện tác động tiêu cực của việc gia tăng dân số quá nhanh ở đới nóng đối với tài nguyên, môi trường.

a) (1/3)⁵⁰ . (-9)²⁵ .2/3:4

= (1/3)⁵⁰ . [-(3)⁵⁰] . 2/3 . 1/4

= - (1/3.3)⁵⁰ . 1/6

= -1 . 1/6 = -1/6

b) (2⁴.2⁶)/(2⁵)² - (2⁵.15³)/(6³.10²)

= 2¹⁰/2¹⁰ - (2⁵.3³.5³)/(2³.3³.2².5²)

= 1- (2⁵.3³.5³)/(2⁵.3³.5²)

= 1- 5

= -4

\(\dfrac{2^4.2^6}{\left(2^5\right)^2}-\dfrac{2^5.15^3}{6^3.10^2}=\dfrac{2^{10}}{2^{10}}-\dfrac{2^5.3^3.5^3}{2^3.3^3.2^2.5^2}\)

=\(1-\dfrac{5^3}{5^2}\) = \(1-5=-4\)

\(\dfrac{x}{3}=\dfrac{y}{5}=\dfrac{z}{7}\) =>\(\dfrac{2x}{6}=\dfrac{3y}{15}=\dfrac{z}{7}\) và 2x+3y-z=-14

Áp dụng dãy tỉ số băng nhau ta có \(\dfrac{2x}{6}=\dfrac{3y}{15}=\dfrac{z}{7}=\dfrac{2x+3y-z}{6+15-7}=\dfrac{-14}{14}=-1\)

=>\(\dfrac{2x}{6}=-1\Rightarrow x=-3\)

\(\dfrac{3y}{15}=-1\Rightarrow y=-5\)

\(\dfrac{z}{7}=-1\Rightarrow z=-7\)

\(\dfrac{2^4\times2^6}{\left(2^5\right)^2}-\dfrac{2^5\times15^3}{6^3\times10^2}\)

\(=\dfrac{2^{10}}{2^{10}}-\dfrac{2^5\times\left(3\times5\right)^3}{\left(2\times3\right)^3\times\left(2\times5\right)^2}\)

\(=1-\dfrac{2^5\times3^3\times5^3}{2^3\times3^3\times2^2\times5^2}\)

\(=1-5\)

\(=-4\)

Chúc bn học tốt

\(=\frac{2^{10}}{2^{10}}-\frac{2^5.3^3.5^3}{2^3.3^3.2^2.5^2}\)

\(=1-5=-4\)

ik nhé. tks bạn!

\(a.=\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{5}{3}+\dfrac{3}{2}+\dfrac{7}{3}-\dfrac{5}{2}=\dfrac{1+3-5}{2}-\dfrac{2+5-7}{3}=\dfrac{-1}{2}\)

\(b.\left(\dfrac{3}{4}-1\dfrac{1}{6}\right)^2:\sqrt{\dfrac{25}{144}}=\left(-\dfrac{5}{12}\right)^2:\dfrac{5}{12}=\dfrac{5}{12}\)

a) -4

b) 5.75

a: =11+3/4-6-5/6+4+1/2+1+2/3

=10+9/12-10/12+6/12+8/12

=10+13/12=133/12

b: \(=2+\dfrac{17}{20}-1-\dfrac{11}{15}+2+\dfrac{3}{20}\)

=3-11/15

=34/15

c: \(=\dfrac{31}{7}:\left(\dfrac{7}{5}\cdot\dfrac{31}{7}\right)\)

\(=\dfrac{31}{7}:\dfrac{31}{5}=\dfrac{5}{7}\)

d: \(=\dfrac{29}{8}\cdot\dfrac{36}{29}\cdot\dfrac{15}{23}\cdot\dfrac{23}{5}=\dfrac{9}{2}\cdot3=\dfrac{27}{2}\)