We are given 2 points with there coordinates easy to calculate:
the upper one A(1,15) & the lower one B(6,10). Moreover the equation of this linear function is y = mx + b
1st) calculate m= (10-15) / (6-1) [FOMULA m=(y₂ - y₁) / (x₂ - x₁)]
m= -5/5 ==> m= - 1==> y=-x + b. To calculate b, replace x & y by any of the 2 points A, B. Say A(1,15)
15 = - (1) + b ==> b= 16 & final equation y = -x +16
let's multiply both sides in each equation by the LCD of all fractions in it, thus doing away with the denominator.
![\begin{cases} \cfrac{1}{2}x+\cfrac{1}{3}y&=7\\\\ \cfrac{1}{4}x+\cfrac{2}{3}y&=6 \end{cases}\implies \begin{cases} \stackrel{\textit{multiplying both sides by }\stackrel{LCD}{6}}{6\left( \cfrac{1}{2}x+\cfrac{1}{3}y \right)=6(7)}\\\\ \stackrel{\textit{multiplying both sides by }\stackrel{LCD}{12}}{12\left( \cfrac{1}{4}x+\cfrac{2}{3}y\right)=12(6)} \end{cases}\implies \begin{cases} 3x+2y=42\\ 3x+8y=72 \end{cases} \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cbegin%7Bcases%7D%20%5Ccfrac%7B1%7D%7B2%7Dx%2B%5Ccfrac%7B1%7D%7B3%7Dy%26%3D7%5C%5C%5C%5C%20%5Ccfrac%7B1%7D%7B4%7Dx%2B%5Ccfrac%7B2%7D%7B3%7Dy%26%3D6%20%5Cend%7Bcases%7D%5Cimplies%20%5Cbegin%7Bcases%7D%20%5Cstackrel%7B%5Ctextit%7Bmultiplying%20both%20sides%20by%20%7D%5Cstackrel%7BLCD%7D%7B6%7D%7D%7B6%5Cleft%28%20%5Ccfrac%7B1%7D%7B2%7Dx%2B%5Ccfrac%7B1%7D%7B3%7Dy%20%5Cright%29%3D6%287%29%7D%5C%5C%5C%5C%20%5Cstackrel%7B%5Ctextit%7Bmultiplying%20both%20sides%20by%20%7D%5Cstackrel%7BLCD%7D%7B12%7D%7D%7B12%5Cleft%28%20%5Ccfrac%7B1%7D%7B4%7Dx%2B%5Ccfrac%7B2%7D%7B3%7Dy%5Cright%29%3D12%286%29%7D%20%5Cend%7Bcases%7D%5Cimplies%20%5Cbegin%7Bcases%7D%203x%2B2y%3D42%5C%5C%203x%2B8y%3D72%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![\bf \stackrel{\textit{using elimination}}{ \begin{array}{llll} 3x+2y=42&\times -1\implies &\begin{matrix} -3x \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~-2y=&-42\\ 3x+8y-72 &&~~\begin{matrix} 3x \\[-0.7em]\cline{1-1}\\[-5pt]\end{matrix}~~+8y=&72\\ \cline{3-4}\\ &&~\hfill 6y=&30 \end{array}} \\\\\\ y=\cfrac{30}{6}\implies \blacktriangleright y=5 \blacktriangleleft \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7Busing%20elimination%7D%7D%7B%20%5Cbegin%7Barray%7D%7Bllll%7D%203x%2B2y%3D42%26%5Ctimes%20-1%5Cimplies%20%26%5Cbegin%7Bmatrix%7D%20-3x%20%5C%5C%5B-0.7em%5D%5Ccline%7B1-1%7D%5C%5C%5B-5pt%5D%5Cend%7Bmatrix%7D~~-2y%3D%26-42%5C%5C%203x%2B8y-72%20%26%26~~%5Cbegin%7Bmatrix%7D%203x%20%5C%5C%5B-0.7em%5D%5Ccline%7B1-1%7D%5C%5C%5B-5pt%5D%5Cend%7Bmatrix%7D~~%2B8y%3D%2672%5C%5C%20%5Ccline%7B3-4%7D%5C%5C%20%26%26~%5Chfill%206y%3D%2630%20%5Cend%7Barray%7D%7D%20%5C%5C%5C%5C%5C%5C%20y%3D%5Ccfrac%7B30%7D%7B6%7D%5Cimplies%20%5Cblacktriangleright%20y%3D5%20%5Cblacktriangleleft%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![\bf \stackrel{\textit{substituting \underline{y} on the 1st equation}~\hfill }{3x+2(5)=42\implies 3x+10=42}\implies 3x=32 \\\\\\ x=\cfrac{32}{3}\implies \blacktriangleright x=10\frac{2}{3} \blacktriangleleft \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill \left(10\frac{2}{3}~~,~~5 \right)~\hfill](https://tex.z-dn.net/?f=%5Cbf%20%5Cstackrel%7B%5Ctextit%7Bsubstituting%20%5Cunderline%7By%7D%20on%20the%201st%20equation%7D~%5Chfill%20%7D%7B3x%2B2%285%29%3D42%5Cimplies%203x%2B10%3D42%7D%5Cimplies%203x%3D32%20%5C%5C%5C%5C%5C%5C%20x%3D%5Ccfrac%7B32%7D%7B3%7D%5Cimplies%20%5Cblacktriangleright%20x%3D10%5Cfrac%7B2%7D%7B3%7D%20%5Cblacktriangleleft%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20~%5Chfill%20%5Cleft%2810%5Cfrac%7B2%7D%7B3%7D~~%2C~~5%20%5Cright%29~%5Chfill)
Answer:
£160,000
Step-by-step explanation:
Alice bought the house in 2008 for £x.
In 2014, the house sold for a 20% profit, so it sold for 1.2x. (* see explanation below)
In 2019, the house sold for a 5% loss, so it sold for 0.95(1.2x). (* see explanation below)
In 2019, it sold for £182,400.
0.95(1.2x) = 182,400
1.14x = 182,400
x = 182,400/1.14
x = 160,000
Answer: £160,000
* Explanation of 1.2 and 0.95.
A quick way to apply a percent increase or decrease to a number is to using the following method. The number you start with is 100% of the number. If you are adding a percent to it, then add the percent to 100% and convert it to a decimal. If you are subtracting the percent, then subtract the percent from 100% and convert to a decimal. Then multiply the decimal by the original number to find the increased or decreased number.
Example of percent increase:
A book used to cost £10. The price went up by 12%. What is the new price?
100% + 12% = 112% = 1.12
1.12 * £10 = £11.20
Example of percent decrease:
A pair of trousers costs £60. It is on sale at 35% off the regular price. What is the sale price?
100% - 35% = 65% = 0.65
0.65 * £60 = £39
Answer:
12,662 books
Step-by-step explanation:
Total number of books = 75,972
No. of science books = ⅓ of 75,972 = ⅓*75,972 = 25,324 books.
No. of business books = 75% of the remaining books = 75% of (75,972 - 25,324)
= 
No. of business books = 37,986
No. of maths books in the math section = 75,972 - (25,324 + 37,986)
= 75,972 - 63,310
= 12,662 books
Water that weighs 325 lbs will fill 5.2 cubic feet.
Step-by-step explanation:
This is a simple question of cross multiplication
<u>DATA:</u>
<em>1. The weight of water for 1 cubic feet is 62.5</em>
<em>2. The weight of water for 'X' cubic feet is 325 </em>
<em>3. To find x, form an equation:</em>
Cubic feet : Weight of water
1 : 62.5
X : 325
<em>4. Cross multiply</em>
X x 62.5 = 1 x 325
62.5X = 325
<em>5. Make X the subject</em>
X = 
<em>6. Solve to find X</em>
X = 5.2 cubic feet
Therefore, water that weighs 325 lbs will fill 5.2 cubic feet.
Key words: Conversion
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