-31x+5 is the same as (-18x-12)-13x+17
It is (d+5)(d+5) because 5•5 is 25 and 5+5 is 10
let's firstly convert the mixed fractions to improper fractions and then proceed.
![\stackrel{mixed}{4\frac{1}{2}}\implies \cfrac{4\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{9}{2}}~\hfill \stackrel{mixed}{1\frac{1}{4}}\implies \cfrac{1\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{5}{4}} \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cstackrel%7Bmixed%7D%7B4%5Cfrac%7B1%7D%7B2%7D%7D%5Cimplies%20%5Ccfrac%7B4%5Ccdot%202%2B1%7D%7B2%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B9%7D%7B2%7D%7D~%5Chfill%20%5Cstackrel%7Bmixed%7D%7B1%5Cfrac%7B1%7D%7B4%7D%7D%5Cimplies%20%5Ccfrac%7B1%5Ccdot%204%2B1%7D%7B4%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B5%7D%7B4%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![\begin{array}{ccll} miles&hours\\ \cline{1-2} \frac{9}{2}&\frac{5}{4}\\[1em] x&1 \end{array}\implies \cfrac{~~ \frac{9}{2}~~}{x}=\cfrac{~~ \frac{5}{4}~~}{1}\implies \cfrac{~~ \frac{9}{2}~~}{\frac{x}{1}}=\cfrac{5}{4}\implies \cfrac{9}{2}\cdot \cfrac{1}{x}=\cfrac{5}{4} \\\\\\ \cfrac{9}{2x}=\cfrac{5}{4}\implies 36=10x\implies \cfrac{36}{10}=x\implies \cfrac{18}{5}=x\implies 3\frac{3}{5}=x](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bccll%7D%20miles%26hours%5C%5C%20%5Ccline%7B1-2%7D%20%5Cfrac%7B9%7D%7B2%7D%26%5Cfrac%7B5%7D%7B4%7D%5C%5C%5B1em%5D%20x%261%20%5Cend%7Barray%7D%5Cimplies%20%5Ccfrac%7B~~%20%5Cfrac%7B9%7D%7B2%7D~~%7D%7Bx%7D%3D%5Ccfrac%7B~~%20%5Cfrac%7B5%7D%7B4%7D~~%7D%7B1%7D%5Cimplies%20%5Ccfrac%7B~~%20%5Cfrac%7B9%7D%7B2%7D~~%7D%7B%5Cfrac%7Bx%7D%7B1%7D%7D%3D%5Ccfrac%7B5%7D%7B4%7D%5Cimplies%20%5Ccfrac%7B9%7D%7B2%7D%5Ccdot%20%5Ccfrac%7B1%7D%7Bx%7D%3D%5Ccfrac%7B5%7D%7B4%7D%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B9%7D%7B2x%7D%3D%5Ccfrac%7B5%7D%7B4%7D%5Cimplies%2036%3D10x%5Cimplies%20%5Ccfrac%7B36%7D%7B10%7D%3Dx%5Cimplies%20%5Ccfrac%7B18%7D%7B5%7D%3Dx%5Cimplies%203%5Cfrac%7B3%7D%7B5%7D%3Dx)
Using a system of equations, it is found that David is 12 years old.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
The variables are given as follows:
- Variable z: Rebecca's age.
David is three times younger than the dad and twice as old as Rebecca, then:
Rebecca is 30 years younger than the dad, hence:
z = y - 30.
Then, since x = 2z and z = y - 30 and y = 3x, we solve for x to find David's age.
x = 2(y - 30)
x = 2(3x - 30)
x = 6x - 60
5x = 60
x = 60/5
x = 12.
David is 12 years old.
More can be learned about a system of equations at brainly.com/question/24342899
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Answer: Domain = 
Range = 
Step-by-step explanation:
Here, the given function,
Since log( negative number ) = not defined
Also,
Hence, f(x) is defined if x - 1 > 0
⇒ x > 1
Thus, f(x) is defined for all the values that are greater than 1,
⇒ Domain of f(x) = All real number greater than 1,
= 
Now, for the interval ,
f(x) can be any real number.
Thus, the range of the given function =
