3x-y=6
y=x-4
solve by substitution
3x-x+4=6
2x=2
x=1
Now that you know x, but in in the equation to find y (either equation will work)
y= 1-4
y= -3
now that you have both answers, let's check them.
3(-1) - (-3) =6
yes, it works....
Hopefully this makes sense!
let's recall that in a Kite the diagonals meet each other at 90° angles, Check the picture below, so we're looking for the equation of a line that's perpendicular to BD and that passes through (-1 , 3).
keeping in mind that perpendicular lines have negative reciprocal slopes, let's check for the slope of BD
so we're really looking for the equation of a line whose slope is -1/3 and passes through point A
![(\stackrel{x_1}{-1}~,~\stackrel{y_1}{3})\qquad \qquad \stackrel{slope}{m}\implies -\cfrac{1}{3} \\\\\\ \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{3}=\stackrel{m}{-\cfrac{1}{3}}[x-\stackrel{x_1}{(-1)}]\implies y-3=-\cfrac{1}{3}(x+1) \\\\\\ y-3=-\cfrac{1}{3}x-\cfrac{1}{3}\implies y=-\cfrac{1}{3}x-\cfrac{1}{3}+3\implies y=-\cfrac{1}{3}x+\cfrac{8}{3}](https://tex.z-dn.net/?f=%28%5Cstackrel%7Bx_1%7D%7B-1%7D~%2C~%5Cstackrel%7By_1%7D%7B3%7D%29%5Cqquad%20%5Cqquad%20%5Cstackrel%7Bslope%7D%7Bm%7D%5Cimplies%20-%5Ccfrac%7B1%7D%7B3%7D%20%5C%5C%5C%5C%5C%5C%20%5Cbegin%7Barray%7D%7B%7Cc%7Cll%7D%20%5Ccline%7B1-1%7D%20%5Ctextit%7Bpoint-slope%20form%7D%5C%5C%20%5Ccline%7B1-1%7D%20%5C%5C%20y-y_1%3Dm%28x-x_1%29%20%5C%5C%5C%5C%20%5Ccline%7B1-1%7D%20%5Cend%7Barray%7D%5Cimplies%20y-%5Cstackrel%7By_1%7D%7B3%7D%3D%5Cstackrel%7Bm%7D%7B-%5Ccfrac%7B1%7D%7B3%7D%7D%5Bx-%5Cstackrel%7Bx_1%7D%7B%28-1%29%7D%5D%5Cimplies%20y-3%3D-%5Ccfrac%7B1%7D%7B3%7D%28x%2B1%29%20%5C%5C%5C%5C%5C%5C%20y-3%3D-%5Ccfrac%7B1%7D%7B3%7Dx-%5Ccfrac%7B1%7D%7B3%7D%5Cimplies%20y%3D-%5Ccfrac%7B1%7D%7B3%7Dx-%5Ccfrac%7B1%7D%7B3%7D%2B3%5Cimplies%20y%3D-%5Ccfrac%7B1%7D%7B3%7Dx%2B%5Ccfrac%7B8%7D%7B3%7D)
Answer:
5 weeks
$175
Step-by-step explanation:
Bill owes his mother $300 and plans to pay her $25 every week.
Therefore, after w weeks he has to give her mother more C = 300 - 25w, amount of money.
Steve owes his mother $550 and plans to pay her $75 every week.
Therefore, after w weeks he has to give her mother more C = 550 - 75w, amount of money.
If after w weeks they both will owe their mother the same amount of money, then
300 - 25w = 550 - 75w
⇒ w = 5 weeks. (Answer)
Now, the amount of money will be $(300 - 25 × 5) = $175. (Answer)
