True AND True is True, if either of the inputs is false the whole thing is false
Answer:(3x1,-4y1) (-4x2,3y2) =y2-y1/x2-x1
Gradient of the line =3-(-4)/-4-3
=3+4/-4-3 =7/-7 =-1
1.
![4x + 5x = 900 \\ 9x = 900 \\ x = 100](https://tex.z-dn.net/?f=4x%20%2B%205x%20%3D%20900%20%5C%5C%209x%20%3D%20900%20%5C%5C%20x%20%3D%20100)
Ratio = 400 : 500
2.
![3x + 7x = 1000 \\ 10x = 1000 \\ x = 100](https://tex.z-dn.net/?f=3x%20%2B%207x%20%3D%201000%20%5C%5C%2010x%20%3D%201000%20%5C%5C%20x%20%3D%20100)
Ratio = 300 : 700
3.
![3x + 5x = 200 \\ 8x = 200 \\ x = 25](https://tex.z-dn.net/?f=3x%20%2B%205x%20%3D%20200%20%5C%5C%208x%20%3D%20200%20%5C%5C%20x%20%3D%2025)
Ratio = 75 : 125
4.
![7x + 8x = 600 \\ 15x = 600 \\ x = 40](https://tex.z-dn.net/?f=7x%20%2B%208x%20%3D%20600%20%5C%5C%2015x%20%3D%20600%20%5C%5C%20x%20%3D%2040)
Ratio = 280 : 320
13.
![7x + 3x + 2x = 120 \\ 12x = 120 \\ x = 10](https://tex.z-dn.net/?f=7x%20%2B%203x%20%2B%202x%20%3D%20120%20%5C%5C%2012x%20%3D%20120%20%5C%5C%20x%20%3D%2010)
Ratio = 70 : 30 : 20
14.
![5x + 6x + 7x = 450 \\ 18x = 450 \\ x = 25](https://tex.z-dn.net/?f=5x%20%2B%206x%20%2B%207x%20%3D%20450%20%5C%5C%2018x%20%3D%20450%20%5C%5C%20x%20%3D%2025)
Ratio = 125 : 150 : 175
15.
![5x + 8x + 9x = 550 \\ 22x = 550 \\ x = 25](https://tex.z-dn.net/?f=5x%20%2B%208x%20%2B%209x%20%3D%20550%20%5C%5C%2022x%20%3D%20550%20%5C%5C%20x%20%3D%2025)
Ratio = 125 : 200 : 225
16.
![3x + 7x + 11x = 13.86 \\ 21x = 13.86 \\ x = 0.66](https://tex.z-dn.net/?f=3x%20%2B%207x%20%2B%2011x%20%3D%2013.86%20%5C%5C%2021x%20%3D%2013.86%20%5C%5C%20x%20%3D%200.66)
Ratio = 1.98 : 4.62 : 7.26
Hope this helps. - M