You add all of the numbers to find
Answer:
![\$1.09](https://tex.z-dn.net/?f=%5C%241.09)
Step-by-step explanation:
All the costs mentioned here are before tax
Let cost of junior bacon cheese burger be ![x](https://tex.z-dn.net/?f=x)
Cost of large fries be ![y](https://tex.z-dn.net/?f=y)
Heather's order cost 12.50
![6x+4y=12.5\quad\ldots (i)](https://tex.z-dn.net/?f=6x%2B4y%3D12.5%5Cquad%5Cldots%20%28i%29)
Sarah's order cost 13.70
![3x+7y=13.7\quad\ldots (ii)](https://tex.z-dn.net/?f=3x%2B7y%3D13.7%5Cquad%5Cldots%20%28ii%29)
Multiply
by ![2](https://tex.z-dn.net/?f=2)
![6x+4y=12.5](https://tex.z-dn.net/?f=6x%2B4y%3D12.5)
![6x+14y=27.4](https://tex.z-dn.net/?f=6x%2B14y%3D27.4)
Subtracting the equations we get
![-10y=-14.9\\\Rightarrow y=\dfrac{14.9}{10}\\\Rightarrow y=1.49](https://tex.z-dn.net/?f=-10y%3D-14.9%5C%5C%5CRightarrow%20y%3D%5Cdfrac%7B14.9%7D%7B10%7D%5C%5C%5CRightarrow%20y%3D1.49)
Cost of large fries is ![\$1.49](https://tex.z-dn.net/?f=%5C%241.49)
![6x+4y=12.5\\\Rightarrow x=\dfrac{12.5-4y}{6}\\\Rightarrow x=\dfrac{12.5-4\times 1.49}{6}\\\Rightarrow x=1.09](https://tex.z-dn.net/?f=6x%2B4y%3D12.5%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B12.5-4y%7D%7B6%7D%5C%5C%5CRightarrow%20x%3D%5Cdfrac%7B12.5-4%5Ctimes%201.49%7D%7B6%7D%5C%5C%5CRightarrow%20x%3D1.09)
Cost of junior bacon cheeseburger before tax is
.
Standard form: Ax+By=C
first put in slope-intercept form:
slope = (0+5)/(6-3) = 5/3
pick point D: 0 = 5/3(6)+b -> b= -10
slope-intercept form: y=(5/3)x-10
multiply both sides by 3:
3y=5x-30
put in standard form:
5x-3y=30
Answer:
x = -4/3
Step-by-step explanation:
2x+10=-4x+2
Add 4x to each side
2x+4x+10=-4x+4x+2
6x +10 = 2
Subtract 10 from each side
6x +10-10 = 2-10
6x = -8
Divide each side by 6
6x/6 = -8/6
x = -4/3