-7 is correct because a negative plus a negative is always a negative
-2x + 8. you multiply all the terms inside the parenthesis by the one outside of/attached to them. the reason it is +8 and not -8 is because the negatives cancel out to give you a positive.
The solution is:A mole of gas occupies 22.4 L A liter is 1000 cubic centimeters because 1 cubic centimeter = 1 mL
One Helium molecule (essentially one helium atom) has atomic mass 4 g/mol So for every 22400 cubic centimeters of volume, we have 4 grams of helium Density of helium = 4g / 22400 cm^3 = 1g / 5600 cm^3
Volume of a sphere = (4/3)(pi)r^3 Volume of the outside sphere (the entire sphere) is (4/3)(pi)(R+T)^3 Volume of the inside sphere (the hollow region) is (4/3)(pi)R^3
The difference for the volume of silver. (4/3)(pi)(R+T)^3 - (4/3)(pi)R^3 = (4/3)(pi)(3R^2T + 3RT^2 + T^3)
The density of silver is 10.5g/cm^3
So the mass of the silver is computed by:10.5*(4/3)(pi)(3R^2T + 3RT^2 + T^3) = (14*pi)(3R^2T + 3RT^2 + T^3) = (14pi)T(3R^2 + 3RT + T^2)
Now for the mass of helium: volume x density = (4/3)(pi)R^3 (1/5600) = (pi/4200)R^3
Set the two masses equal: (pi/4200)R^3 = (14pi)T(3R^2 + 3RT + T^2) R^3 = 58800*T(3R^2 + 3RT + T^2) R / T = 58800*(3R^2 + 3RT + T^2) / R^2 = 58800*( 3+T/R^2+(T/R)^2)
then solve for xx = T / R 1/x = 58800*( 3+x/R+x^2) 1/58800 = x (3 + x/R + x^2) 1/58800 = 3x + x^3 x^3 + 3x - 1/58800= 0 x = ~ 5.66893x10^(-6)
Answer:
42.8°
Step-by-step explanation:
The sine rule states that for a triangle with lengths of a, b and c and the corresponding angles which are opposite the sides as A, B and C, then the following rule holds:

Given that points A, B and C forms a triangle with angle A = 65°, distance from A-to-C = 90 m and the distance from B to C = 120 m.
The distance from A to C is the side opposite to angle B. Hence let b = distance from A to C = 90 m.
The distance from B to C is the side opposite to angle A. Hence let a = distance from B to C = 120 m.
Therefore using sine rule:

Answer:
2.3 liters
Step-by-step explanation:
800 ml (milliliters) = 0.8 l (liters)
1.5 + 0.8 = 2.3 l