1st one: 8x+1
2nd one:5m+4
let's say the original price is "x", so that'd be the 100%.
and we know that is discounted by 30%, 100% - 30% = 70%, we know the discounted price is 206.50, so namely 206.50 is the 70% then.
if 206.50 is 70% of "x", what is "x"?
![\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 206.50&70\\ x&100 \end{array}\implies \cfrac{206.50}{x}=\cfrac{70}{100}\implies \cfrac{206.50}{x}=\cfrac{7}{10} \\\\\\ 2065=7x\implies \cfrac{2065}{7}=x\implies 295=x](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Barray%7D%7Bccll%7D%20amount%26%5C%25%5C%5C%20%5Ccline%7B1-2%7D%20206.50%2670%5C%5C%20x%26100%20%5Cend%7Barray%7D%5Cimplies%20%5Ccfrac%7B206.50%7D%7Bx%7D%3D%5Ccfrac%7B70%7D%7B100%7D%5Cimplies%20%5Ccfrac%7B206.50%7D%7Bx%7D%3D%5Ccfrac%7B7%7D%7B10%7D%20%5C%5C%5C%5C%5C%5C%202065%3D7x%5Cimplies%20%5Ccfrac%7B2065%7D%7B7%7D%3Dx%5Cimplies%20295%3Dx)
increasing 20 to 40 is the same as increasing 20 by 20 (or itself), so it is a 100% increase. Decreasing 40 to 20 is the same as decreasing 40 by 1/2 or by 20. So it is a 50% increase.
when going from 20 to 40, the number is being doubled, and when youre going from 40 to 20 you are cutting the number in half.
hope this helped:)
No not all diagonal lines are lines of symmetry! Because if you take a piece of notebook paper and fold it in half the side do not match up! hope this helps :)