6
9x is rate of function
3x is rate of function
y=mx+b
Answer:
![Cost\ of\ donut=\frac{49}{24}\approx \$2.042\\\\cost\ of\ donuts=\frac{49}{4}\approx \$12.25](https://tex.z-dn.net/?f=Cost%5C%20of%5C%20donut%3D%5Cfrac%7B49%7D%7B24%7D%5Capprox%20%5C%242.042%5C%5C%5C%5Ccost%5C%20of%5C%20donuts%3D%5Cfrac%7B49%7D%7B4%7D%5Capprox%20%5C%2412.25)
Step-by-step explanation:
a.
![Let\ cost\ of\ coffee=y\\\\cost\ of\ one\ donut=x\\\\Each\ friend\ buy\ one\ coffee\ and\ two\ donuts\\\\Amount\ for\ 1\ friend=Cost\ of\ coffee+2\times cost\ of\ donut\\\\Amount\ for\ 1\ friend=y+2x\\\\Amount\ required\ for\ 3\ friend=3\times Amount\ for\ 1\ friend\\\\Amount\ required\ for\ 3\ friend=3\times (y+2x)\\\\Amount\ required\ for\ 3\ friend=3y+6x\\\\Total\ bill=\$ 22\\\\3y+2x=22\\\\Given\ cost\ of\ coffee=\$3.25\\\\y=\$3.25](https://tex.z-dn.net/?f=Let%5C%20cost%5C%20of%5C%20coffee%3Dy%5C%5C%5C%5Ccost%5C%20of%5C%20one%5C%20donut%3Dx%5C%5C%5C%5CEach%5C%20friend%5C%20buy%5C%20one%5C%20coffee%5C%20and%5C%20two%5C%20donuts%5C%5C%5C%5CAmount%5C%20for%5C%201%5C%20friend%3DCost%5C%20of%5C%20coffee%2B2%5Ctimes%20cost%5C%20of%5C%20donut%5C%5C%5C%5CAmount%5C%20for%5C%201%5C%20friend%3Dy%2B2x%5C%5C%5C%5CAmount%5C%20required%5C%20for%5C%203%5C%20friend%3D3%5Ctimes%20Amount%5C%20for%5C%201%5C%20friend%5C%5C%5C%5CAmount%5C%20required%5C%20for%5C%203%5C%20friend%3D3%5Ctimes%20%28y%2B2x%29%5C%5C%5C%5CAmount%5C%20required%5C%20for%5C%203%5C%20friend%3D3y%2B6x%5C%5C%5C%5CTotal%5C%20bill%3D%5C%24%2022%5C%5C%5C%5C3y%2B2x%3D22%5C%5C%5C%5CGiven%5C%20cost%5C%20of%5C%20coffee%3D%5C%243.25%5C%5C%5C%5Cy%3D%5C%243.25)
![Hence\ solution\ of\ following\ system\ of\ equation\ will\ give\ cost\ of\ donut:\\\\3y+6x=22\\\\y=3.25\\\\\\Substitute\ y=3.25\ in\ first\ equation\\\\3\times 3.25+6x=22\\\\9.75+6x=22\\\\6x=22-9.75\\\\6x=12.25\\\\x=\frac{12.25}{6}\\\\x=\frac{49}{24}\approx \$2.042\\\\Cost\ of\ donut=\frac{49}{24}\approx \$2.042](https://tex.z-dn.net/?f=Hence%5C%20solution%5C%20of%5C%20following%5C%20system%5C%20of%5C%20equation%5C%20will%5C%20give%5C%20cost%5C%20of%5C%20donut%3A%5C%5C%5C%5C3y%2B6x%3D22%5C%5C%5C%5Cy%3D3.25%5C%5C%5C%5C%5C%5CSubstitute%5C%20y%3D3.25%5C%20in%5C%20first%5C%20equation%5C%5C%5C%5C3%5Ctimes%203.25%2B6x%3D22%5C%5C%5C%5C9.75%2B6x%3D22%5C%5C%5C%5C6x%3D22-9.75%5C%5C%5C%5C6x%3D12.25%5C%5C%5C%5Cx%3D%5Cfrac%7B12.25%7D%7B6%7D%5C%5C%5C%5Cx%3D%5Cfrac%7B49%7D%7B24%7D%5Capprox%20%5C%242.042%5C%5C%5C%5CCost%5C%20of%5C%20donut%3D%5Cfrac%7B49%7D%7B24%7D%5Capprox%20%5C%242.042)
See attached diagram.
b.
![Each\ friend\ takes\ 2\ donuts\\\\Total\ donuts=Number\ of\ friends\times 2\\\\Total\ donuts=3\times 2=6\\\\cost\ of\ donuts=number\ of\ donuts\times cost\ of\ 1\ donut\\\\cost\ of\ donuts=6\times \frac{49}{24}\\\\cost\ of\ donuts=\frac{49}{4}\approx \$12.25](https://tex.z-dn.net/?f=Each%5C%20friend%5C%20takes%5C%202%5C%20donuts%5C%5C%5C%5CTotal%5C%20donuts%3DNumber%5C%20of%5C%20friends%5Ctimes%202%5C%5C%5C%5CTotal%5C%20donuts%3D3%5Ctimes%202%3D6%5C%5C%5C%5Ccost%5C%20of%5C%20donuts%3Dnumber%5C%20of%5C%20donuts%5Ctimes%20cost%5C%20of%5C%201%5C%20donut%5C%5C%5C%5Ccost%5C%20of%5C%20donuts%3D6%5Ctimes%20%5Cfrac%7B49%7D%7B24%7D%5C%5C%5C%5Ccost%5C%20of%5C%20donuts%3D%5Cfrac%7B49%7D%7B4%7D%5Capprox%20%5C%2412.25)
(17.5)(x)=125
Divide each side by 17.5 leaving the equation as x=7.14
Answer:
89
Step-by-step explanation:
I just multiplied 320 by 0.2 and then 250 by 0.1 and then added them together. I hope it helps and I'm not sure what method you would use for this but that's mine.
Answer:
49/4
Step-by-step explanation:
x² -7x +(7/2)²=(x-7/2)²
x²-2x·7/2+ (7/2)²=(x²-7/2)²
(7/2)²=49/4