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:
1/3
3/10
6/8 or 3/4
Step-by-step explanation:
Answer:the distance if the whole trip is 280 miles
Step-by-step explanation:
Let x represent the distance of the whole trip.
Jordans family is on a road tirp. So far they have travelled 3/7 of the total distance. This means that the distance that they have travelled so far is
3/7 × x = 3x/7
They have travelled 120 miles so far. This means that
3x/7 = 120
Multiplying both sides if the equation by 7, it becomes
3x/7 × 7 = 120 × 7
3x = 840
Dividing both sides of the equation by 3, it becomes
3x/3 = 840/3
x = 280 miles
Answer:
(0,4)
Step-by-step explanation:
Here, we want to find the y-intercept of the quadratic function
g(x) = 5x^2 + 9x + 4
Mathematically, we know that the y-intercept is the position on the graph where we have x = 0
so, to find the y-intercept value, we have to find g(0)
simply put, we have to substitute the value of 0 for x
Mathematically, we have this as;
g(0) = 5(0)^2 + 9(0) + 4
g(0) = 0 + 0 + 4
g(0) = 4
thus, we have the y-intercept point as (0,4)