OK. These problems are easy if you know the quadratic formula,
and they're impossible if you don't.
Here's the quadratic formula:
When the equation is in the form of Ax² + Bx + C = 0
then x = [ -B plus or minus √(B²-4AC) ] / 2A
I'm sure that formula is in your text or your study notes,
right before these questions. You should cut it out or
copy it, and tape it inside the cover of your notebook.
Then, you'll always have it when you need it, until
you have it memorized and can rattle it off.
The first question says 3x² + 5x + 2 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes ! A=3 B=5 C=2
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
= [ -5 plus or minus √(5² - 4·3·2) ] / 2·3
= [ -5 plus or minus √(25 - 24) ] / 6
= [ -5 plus or minus √1 ] / 6
x = -4 / 6 = -2/3
and
x = -6 / 6 = -1 .
_______________________________________
The second question says
4x² + 5x - 1 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes it is ! A=4 B=5 C= -1
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
Now, you take it from here.
Answer:
<h2>$12.6</h2>
Step-by-step explanation:
Step one:
given that the dimensions are
length=3cm
width=4cm
hieght= 7cm
the volume of the pool is= lwh
volume=3*4*7= 84cm^3
Step two:
the cost of filling
we are told that 1cm^3 will cost $0.15
hence 84cm^3 will cost x
cross multiply
x= 0.15*84
x=12.6
<u>The cost of filling the pool will be $12.6</u>
Answer:
The dimension of the sandbox is (2x+1) by (x - 3)
Step-by-step explanation:
It seems the complete question will be:
The area of sandbox in park is represented by 2X^2-5x-3 find the dimensions of the sandbox in terms of x.
Step-by-step explanation:
From the question, the given expression is 2X^2-5x-3. This can be rewritten as
If the area of the sandbox in park is represented by this expression, then the dimensions of the sandbox will be the product of the factors. To determine the factors, we will factorize the given quadratic expression.
Factorizing the expression , we get
Hence, the dimension of the sandbox is (2x+1) by (x - 3)
Answer: x = 77 degrees, y = 77 degrees, z = 103 degrees
Step-by-step explanation:
Since y and 103 are essentially same side interior angles, they must add up to 180. Therefore, y = 180-103 = 77 degrees.
Opposite angles of a paralellogram are equal.
Therefore, x = y = 77 degrees and z = 103 degrees
