21*10=210
30*7=210
42*5=210
14*15=210
Using a system of equations, it is found that Peter had $48 at first.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, the variables are:
- Variable x: Peter's money.
- Variable y: Henry's money.
The ratio of peters money to henrys money is 4 : 3, hence:

After Peter spent $12, they had the same amount, hence:
y = x - 12.
Then, replacing in the ratio:


4(x - 12) = 3x
x = 48.
More can be learned about a system of equations at brainly.com/question/24342899
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<u>Answer:</u>
Lengths of the sides (there are 3 sides in an equilateral triangle) of the base of prism is <u>5.72cm </u>each.
<u>Step-by-step explanation:</u>
As the base of triangular prism is equilateral:
∴ Area of base = (√ 3 / 4)× (side)²
According to question:
height of prism = height (side) of base
Volume of prism = 81 cm³,
∴ Volume of prism = Area of base x height
⇒ 81 cm³ = (√ 3 / 4)× (side)² × height ∵ side = height
⇒ 81 cm³ = (√ 3 / 4)× (side)³
⇒ 81 × (4/√3) cm³ = side³
⇒ ∛(81 × (4/√3) cm = side
⇒ side = <u>5.72cm</u>
Answer:
The angle of elevation of the ramp is 64.60°
Step-by-step explanation:
Given;
length of the ramp, L = 35 ft
distance of the platform to the foot of the ramp, d = 15 ft
The length of the ramp forms the hypotenuse side of this right angled triangle;
The angle of elevation of the ramp is in angle between the hypotenuse and adjacent side of the triangle.
Cos x = adjacent / hypotenuse
Cos x = 15 / 35
Cos x = 0.4286
x = Cos⁻¹ (0.4286)
x = 64.62
x = 64.60°
Therefore, the angle of elevation of the ramp is 64.60°