Carol has only 20p and 10p coins in her purse she has three times as many 20p coins and 10p coins if Carol has ?4.20 altogether,
2 answers:
Suppose that Carol has x 10p coins in her purse. Since she has three times as many 20p coins as 10p coins, then she has 3x 20p coins in her purse.
x coins of 10p value $0.10x and 3x coins of 20p value $0.60x.
In total this amount of money is $(0.10x+0.60x)=$0.70x that is exactly $4.20. Thus, you get the equation
0.70x=4.20.
Solve it:
Carol has 6 coins of 10p and 3·6=18 coins of 20p.
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Answer:
The point of intersection of the system of equations is:
(x, y) = (-2, 1)
The correct system of equations intersect at point A in this graph will be:
Thus, the second option is correct.
Step-by-step explanation:
Given the point
- A (-2, 1)
Let us check the system of equations to determine whether it intersect at point A in this graph.
Given the system of equations
Arrange equation variable for elimination
so
so the system of equations becomes
Solve 7x = -14 for x
Divide both sides by 7
Simplify
For y - 4x = 9 plug in x = 2
Subtract 8 from both sides
Simplify
y = 1
Thus, the solution to the system of equations is:
(x, y) = (-2, 1)
From the attached graph, it is also clear that the system of equations intersects at point x = -2, and y = 1.
In other words, the point of intersection of the system of equations is:
(x, y) = (-2, 1)
Therefore, the correct system of equations intersect at point A in this graph will be:
Thus, the second option is correct.
61.23 square inches of metal is needed to create a cylindrical can.
Solution:
Diameter of the base = 3 in
Radius of the base = 3 ÷ 2 = 1.5 in
Height of the cylinder = 5 in
The value of π = 3.14
<u>To find the surface area of the cylinder:</u>
Surface area of the cylinder =
= 2 × 3.14 × (1.5)² + 2 × 3.14 × 1.5 × 5
= 14.13 + 47.1
Surface area of the cylinder = 61.23 sq. in
Hence 61.23 square inches of metal is needed to create a cylindrical can.