Answer:
x = 1 ±2sqrt(5)
Step-by-step explanation:
2x^2-4x-9=29
Add 9 to each each side
2x^2-4x-9+9=29+9
2x^2-4x=38
Divide by 2
2/2x^2-4/2x=38/8
x^2 -2x =19
Complete the square
x^2 -2x + (-2/2)^2 = 19 +(-2/2)^2
x^2 -2x +1 = 19+1
(x-1)^1=2 = 20
Take the square root of each side
sqrt((x-1)^2) = ±sqrt(20)
x-1 = ±sqrt(20)
Add 1 to each side
x-1+1 = 1 ±sqrt(20)
x = 1 ±sqrt(20)
Simplifying the square root of 20
x = 1 ±sqrt(4)sqrt(5)
x = 1 ±2sqrt(5)
Answer:
31.5 litres
Step-by-step explanation:
If Mel uses all 30 litres of yellow paint, then:
5 / 2 = 30 / x
5x = 60
x = 12
Mel would need 12 litres of blue paint, but she only has 9 litres. So the amount of yellow paint she needs is:
5 / 2 = x / 9
2x = 45
x = 22.5
Mel will use 22.5 litres of yellow paint with 9 litres of blue paint to make a total of 31.5 litres of green paint.
So,
We need to convert the gallons into cups.
1 gal. = 16 c.
2 3/4 gal. = 2(16) + 3/4(16) = 32 + 12 = 44
3 5/8 gal. = 3(16) + 5/8(16) = 48 + 10 = 58
5 gal. = 5(16) = 80
There are 20 + 15 = 35 people. Therefore, Bob's friends will drink a total of 35 cups of lemonade, 35 cups of punch, and 35 cups of soda. We just need to subtract these amounts from what Bob has.
44 - 35 = 9 cups of lemonade
58 - 35 = 23 cups of punch
80 - 35 = 45 cups of soda
Obviously, then, Bob will have enough drinks.
He has 9 cups of lemonade, 23 cups of punch, and 45 cups of soda left over. In gallons, he has 9/16 gallons of lemonade, 1 7/16 gallons of punch, and 2 13/16 gallons of soda left over.
Well if you're solving for x this would be rather simple. 7x +1=68 , then you'd minus 1 from both sides. 7x = 67 then divide 67 by 7. The answer isn't a whole number so x would either be 67/7 or 9.57.. etc.
