Answer:
Step-by-step explanation:
5
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,
![\frac{ L - 5}{X - 5} = \frac{2}{5}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%20L%20-%205%7D%7BX%20-%205%7D%20%20%3D%20%20%5Cfrac%7B2%7D%7B5%7D%20)
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,
![\frac{L + 9}{X + 9} = \frac{3}{4}](https://tex.z-dn.net/?f=%20%5Cfrac%7BL%20%2B%209%7D%7BX%20%2B%209%7D%20%20%3D%20%20%5Cfrac%7B3%7D%7B4%7D%20)
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.
We are given the range of the data that is from 2.35 grams to 4.75 grams- we can call these two the lower and upper llimits respectively. In this case, to find the first class limits, we have to divide the range into 12. The range is 2.40 grams made up of 12 parts of 0.2 grams. The first class hence limits are
lower: 2.35 g
upper: 2.35+0.2 =2.55 g
Answer:
4.5
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The table follows a linear pattern
The equation that represents the date on the table is C=0.25m + 8.95
<h3>What are linear patterns?</h3>
Linear patterns are equations that have constant rates or slopes
<h3>How to calculate the equation</h3>
From the table, we have the following ordered pair
(m,C) = (50,21.45) and (100, 33.95)
We start by calculating the slope using:
![s = \frac{C_2 -C_1}{m_2 -m_1}](https://tex.z-dn.net/?f=s%20%3D%20%5Cfrac%7BC_2%20-C_1%7D%7Bm_2%20-m_1%7D)
So, we have:
![s = \frac{33.95 - 21.45}{100 - 50}](https://tex.z-dn.net/?f=s%20%3D%20%5Cfrac%7B33.95%20-%2021.45%7D%7B100%20-%2050%7D)
![s = \frac{12.5}{50}](https://tex.z-dn.net/?f=s%20%3D%20%5Cfrac%7B12.5%7D%7B50%7D)
![s = 0.25](https://tex.z-dn.net/?f=s%20%3D%200.25)
The equation is then calculated using:
![C=s(m - m_1) + C_1](https://tex.z-dn.net/?f=C%3Ds%28m%20-%20m_1%29%20%2B%20C_1)
So, we have:
![C=0.25(m - 50) + 21.45](https://tex.z-dn.net/?f=C%3D0.25%28m%20-%2050%29%20%2B%2021.45)
Open the bracket
![C=0.25m - 12.5 + 21.45](https://tex.z-dn.net/?f=C%3D0.25m%20-%2012.5%20%2B%2021.45)
![C=0.25m + 8.95\\](https://tex.z-dn.net/?f=C%3D0.25m%20%2B%208.95%5C%5C)
Hence, the equation of the total cost is C=0.25m + 8.95
Read more about linear equations at:
brainly.com/question/14323743