Answer:
a=20
Step-by-step explanation:
7+13=20
20-7=13
Answer:
he had $90
he bought a phone for $75
90-75=15
he has $15 now
15÷0.06=1500÷6=250 minutes
This is the formula to solve for the vertex.
Example Question:
Find the vertex of y = -0.5x^2 + 100x
-b/2a = -100/2(-0.5) = -100/-1 = 100
The x coordinate of the vertex is 100.
Best of Luck!
P.S. this is 1000th question i've answered :)
Start by writing the system down, I will use
to represent 

Substitute the fact that
into the first equation to get,

Simplify into a quadratic form (
),

Now you can use Vieta's rule which states that any quadratic equation can be written in the following form,

which then must factor into

And the solutions will be
.
Clearly for small coefficients like ours
, this is very easy to figure out. To get 5 and 6 we simply say that
.
This fits the definition as
and
.
So as mentioned, solutions will equal to
but these are just x-values in the solution pairs of a form
.
To get y-values we must substitute 3 for x in the original equation and then also 2 for x in the original equation. Luckily we already know that substituting either of the two numbers yields a zero.
So the solution pairs are
and
.
Hope this helps :)
Answer:
Step-by-step explanation:
1/2 multiplied by (12 multiplied by 2)
1/2 (24)
= 12 inches grown + 23 inches
= 35 inches long