Answer:
The solutions are a₁ = -4/19 i, a₂ = 4/19 i and a₃ = -1/4
Step-by-step explanation:
Given the equation 76a³+19a²+16a=-4, for us to solve the equation, we need to find all the factors of the polynomial function. Since the highest degree of the polynomial is 3, the polynomial will have 3 roots.
The equation can also be written as (76a³+19a²)+(16a+4) = 0
On factorizing out the common terms from each parenthesis, we will have;
19a²(4a+1)+4(4a+1) = 0
(19a²+4)(4a+1) = 0
19a²+4 = 0 and 4a+1 = 0
From the first equation;
19a²+4 = 0
19a² = -4
a² = -4/19
a = ±√-4/19
a₁ = -4/19 i, a₂ = 4/19 i (√-1 = i)
From the second equation 4a+1 = 0
4a = -1
a₃ = -1/4
- subtract the 12 from both sides so that it becomes the last constant term in the quadratic equation which should now equal 0.
- take the 4x
- half the coefficient of 4 (2)
- square it (4)
- add it to the equation (+4)
- subtract it from the equation (-4)
- factorise the square (x+2)^2 expands to (x^2 + 4x + 2) as {a+b}^2={a^2 + ab + ba + b^2}
- now the equation is in turning point form.
- to find x, add 16 and square root 16 and (x+2)
- subtract 2 from positive or negative 4 (as -4^2 and 4^2 both equal 16).
- This should give you two values for x, -6 and 2.
I really hope that this helped :)
24w+6c=$23.40
5w+2c=$6.60
So you have to find c (chips) first. You have to make the number of chips in both equations cancel each other.
-3(5w+2c)=-3($6.60)
-15w-6c=$-19.80
Then subtract to get one formula
24w + 6c = $23.40
-15w - 6c = $-19.80
9w = $3.60
w=$.40
To check your answer, find how much one bag of chips costs:
5($.40) + 2c = $6.60
$2.00 + 2c = $6.60
2c = $4.60
c=$2.30
Plug your value for one water and one bag of chips into the formula:
5($.40) + 2($2.30)
$2.00 + $4.60
=$6.60
Then plug your values into the original problem:
24($.40) + 6($2.30)
$9.60 + $13.80
=$23.40
To get an average of at least a 70, Paul would have to get at least a 66 on his third test.
