Answer:
A
Step-by-step explanation:
formula is A=2a2+4ah
A= 2*5^2+4*5*5
A=50+100
A=150
Answer:
Paige would study 2 subjects.
Step-by-step explanation:
Paige would study for one hour. She spends 1/2 an hour, or 30 minutes, on a subject.
An hour is 60 minutes. If Paige studied 2 subjects, then she would of studied for 60 minutes.
30 + 30 = 60
So, if Paige spends 1/2 hour on Spanish, she would study 2 subjects to reach an hour.
Use the quadratic formula to find the solutions:<span><span><span>−b±<span>√<span><span>b2</span>−4<span>(ac)</span></span></span></span><span>2a</span></span><span><span>-b±<span><span>b2</span>-4<span>(ac)</span></span></span><span>2a </span></span></span>Substitute the values:
<span><span>a=−1</span><span>a=-1</span></span>, <span><span>b=0</span><span>b=0</span></span>, and <span><span>c=40</span><span>c=40 </span></span> into the quadratic formula and solve for <span>x </span><span><span><span>0±<span>√<span><span>02</span>−4⋅<span>(−1⋅40)</span></span></span></span><span>2⋅−1</span></span><span><span>0±<span><span>02</span>-4⋅<span>(-1⋅40)</span></span></span><span>2⋅-1 </span></span></span>Simplify:
<span><span>x=±2<span>√10</span></span><span>x=±210 </span></span>The result can be shown in both exact and approximate form: <span><span>x=±2<span>√10</span></span><span>x=±210</span></span><span>x≈6.324555,−<span>6.324555
<em />I hope this helps. :)
</span></span>
Explanation:
We want this in the form
y
=
m
x
+
c
, where
m
is the gradient, and
c
is the y-intercept.
Gradient is the change in y over the change in x, or the rise over run; however you like to think about it.
m
=
y
2
−
y
1
x
2
−
x
1
So for our points
(
1
,
4
)
and
(
4
,
9
)
m
=
9
−
4
4
−
1
=
5
3
Now, by rearranging our equation for gradient, we can show that:
y
−
y
1
=
m
(
x
−
x
1
)
Here,
x
and
y
are general points on the line - we've just replaced
(
x
2
,
y
2
)
with
(
x
,
y
)
Since we know
m
, and have a set of co-ordinates to sub in as
(
x
1
,
y
1
)
, we can sub values in, then re-arrange to get to the
y
=
m
x
+
c
form.
y
−
4
=
5
3
(
x
−
1
)
y
−
4
=
5
3
x
−
5
3
y
=
5
3
x
−
5
3
+
4
y
=
5
3
x
+
7
3
as required.
