Questions in Grade High-school

Questions in Grade High-school

[Done] What value of [tex]$x$[/tex] makes the following equation true? [tex]\frac{3}{4}(7+x)=12[/tex] A. 2 B. [tex]$6 \frac{1}{4}$[/tex] C. 9 D. [tex]$17 \frac{1}{4}$[/tex]

[Done] What is the empirical formula of $C _8 H _{16} O _8$?

[Done] A cylinder has a volume of $288 \pi$ cubic meters and a height of 9 meters. What is the area of the base? A. $32 \pi$ square meters B. $18 \pi$ square meters C. $279 \pi$ square meters D. $2,592 \pi$ square meters

[Done] Dalia flies an ultralight plane with a tailwind to a nearby town in [tex]$1 / 3$[/tex] of an hour. On the return trip, she travels the same distance in 3/5 of an hour. What is the average rate of speed of the wind and the average rate of speed of the plane? Initial trip: [tex]$3 / 5$[/tex] hours Return trip: Let [tex]$x$[/tex] be the average airspeed of the plane. Let [tex]$y$[/tex] be the average wind speed. Initial trip: [tex]$18=(x+y) \frac{1}{3}$[/tex] Return trip: [tex]$18=(x-y) \frac{3}{5}$[/tex] Dalia had an average airspeed of [ ] miles per hour. The average wind speed was [ ] miles per hour.

[Done] Select the correct answer. Which behavior reduces your risk for heart disease? A. completing low-intensity activities B. taking your pulse C. eating five small meals each day D. exercising

[Done] The point $A(-5,3)$ and the point $B$ have midpoint $(4,-2)$. Find the coordinates of $B$.

[Done] $-\frac{6}{7}+\left(-\frac{4}{7}\right)$

[Done] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Done] Which factor can decrease the rate of a chemical reaction? A. low activation energy B. high pressure C. low temperature D. high concentration of enzyme

[Done] Which of the following reactions are disproportionation reactions? (A) Cu⁺ → Cu²⁺ + Cu (B) 2 KMnO₄ → K₂MnO₄ + MnO₂ + 2 H₂O (C) 2 KMnO₄ → K₂MnO₄ + MnO₂ + O₂ (D) 2 MnO₄⁻ + 3 Mn²⁺ + 2 H₂O → 5 MnO₂ + 4 H⁺ Choose the correct answer from the options given below: (A), (B)