Answer:
10c = 20
5c = 5
Step-by-step explanation:
Let x be the number of 10c coins; let y be the number of 5c coins. The total is $2.25, so the amount of 10c and 5c coins will add to that. Simita has 25 coins, so x and y, the number of coins, will have to add to 25. Hence, solve the simultaneous equation.
10x + 5y = 225 (1) - times by 0
x + y = 25 (2) - times by 5
10x + 5y = 225 (1)
5x + 5y = 125 (2)
Then, take equation 2 away from equation 1.
5x = 100
x = 20
Substitute x back into the original equation.
x + y = 25
20 + y = 25
y = 5
Answer: D = 70
A = 30
Explanation: d is parallel to 70 degrees, 40 is parallel to e, and the whole set of angles is 180 so 180 - 2(70) + 2(40) = 30 so D = 70 and A = 30
72 is 266.666666667% of 27
Density is mass per unit volume.
For the given material that has a mass of 44 grams occupying a volume of 6 cm^3, we divide the mass by the volume, i.e.
density of material = 44 grams / 6 cm^3 = 44/6 grams/cm^3 = 7.3 g/cm^3 (to two significant figures)
