Answer:
15 years old
Step-by-step explanation:
Start by defining the variables that we are going to use throughout our working:
Let the current age of Wei Ling and Wei Xuan be L and X years old respectively.
Next, form equations using the given information.
<u>5 years </u><u>ago</u>
Wei Ling: (L -5) years old
Wei Xuan: (X -5) years old
Given that the ratio of Wei Ling's age to that of Wei Xuan's is 2: 5,
Cross multiply:
2(X -5)= 5(L -5)
Expand:
2X -10= 5L -25
2X= 5L -25 +10
2X= 5L -15 -----(1)
<u>9 years time</u>
Wei Ling: (L +9) years old
Wei Xuan: (X +9) years old
Given that the ratio of Wei Ling's age to that of Wei Xuan is 3: 4,
Cross multiply:
3(X +9)= 4(L +9)
Expand:
3X +27= 4L +36
3X= 4L +36 -27
3X= 4L +9 -----(2)
Let's solve using the elimination method.
(1) ×3:
6X= 15L -45 -----(3)
(2) ×2:
6X= 8L +18 -----(4)
(3) -(4):
6X -6X= 15L -45 -(8L +18)
0= 15L -45 -8L -18
0= 7L -63
7L= 63
L= 63 ÷7
L= 9
Substitute L= 9 into (1):
2X= 5(9) -15
2X= 45 -15
2X= 30
X= 30 ÷2
X= 15
Thus, Wei Xuan is 15 years old now.
Answer:
<h2>
h(x) = 0.0065x+1.25</h2>
Step-by-step explanation:
Given the time length in hours of a certain airplane flight represented by the function f(x) = 0.0025x + 0.75.
The time length of another airplane flight in hours can be represented by the function g(x) = 0.004x + 0.5.
x is the number of miles for the flight
The function that represents the sum of the flight time lengths is given as h(x) as shown;
h(x) = f(x) + g(x)
To get h(x), we will substitute the functions f(x) and g(x) into formula for function h(x) as shown below;
h(x) = (0.0025x + 0.75)+(0.004x + 0.5)
Collecting the like terms;
h(x)= 0.0025x + 0.004x + 0.75 + 0.5
h(x) = 0.0065x+1.25
This gives the sum of the flight time lengths
To find angle, the equation is:
b+81=180
Answer: Equation is : b + 81° = 180°
So since there are 2 placeholders, the answer are many, but we can make into slope intercept form to make it easier to solve (slope intercept form is y=mx+b)
15x-12y=60
15x-60-15y=0
15x-60=12y
12y=15x-60
divide both sides by 3
4y=5x-20
divide both sides by 4
y=5/4x-5
just put in values for x and get y so exg
(x,y)
0,-5
1,-15/4
2,-5/2
3,-5/4
4,0
and so on