<h3>
Answer: Choice D. 4x^2 + 20x + 25</h3>
===============================================
Explanation:
Perfect square trinomials are in the form (a+b)^2 = a^2+2ab+b^2
So the first and last terms must be perfect squares. The middle term is twice that of the square roots of each first and last term.
Choice D fits the description because 4x^2 = (2x)^2 is the first term, so a = 2x and 25 = 5^2 is the last term meaning b = 5. Note how 2ab = 2*2x*5 = 20x is the middle term.
-------------
(a+b)^2 = a^2+2ab+b^2
(2x+5)^2 = (2x)^2+2*2x*5+5^2
(2x+5)^2 = 4x^2 + 20x + 25
Answer:3
x
−
2
y
=
7
Explanation:
Write the standard form of the line that goes through
(
3
,
1
)
and is perpendicular to
y
=
−
2
3
x
+
4
.
The equation
y
=
−
2
3
x
+
4
is in slope intercept form
y
=
m
x
+
b
where
m
= slope and
b
= the
y
intercept.
The slope of this line is then
m
=
−
2
3
A perpendicular slope is the opposite sign reciprocal. So, we change the sign of
−
2
3
and switch the numerator and denominator.
Perpendicular slope
m
=
3
2
To find the equation of the new line, use the point slope equation
y
−
y
1
=
m
(
x
−
x
1
)
where
m
=
slope and
(
x
1
,
y
1
)
is a point.
The slope is
3
2
and the point is the given point
(
3
,
1
)
.
y
−
1
=
3
2
(
x
−
3
)
a
a
a
Distribute
y
−
1
=
3
2
x
−
9
2
Standard form is
a
x
+
b
y
=
c
where
a
,
b
and
c
are integers and
a
is positive.
a
a
2
(
y
−
1
=
3
2
x
−
9
2
)
a
a
a
Multiply the equation by
2
a
a
a
a
a
2
y
−
2
=
3
x
−
9
−
3
x
a
a
a
a
a
a
a
−
3
x
a
a
a
Subtract
3
x
from both sides
−
3
x
+
2
y
−
2
=
−
9
a
a
a
a
a
a
a
a
+
2
a
a
a
+
2
a
a
a Add 2 to both sides −
3
x
+
2
y
=
−
7
−
1
(
−
3
x
+
2
y
=
−
7
)
a
a
a
Multiply the equation by −
1
3
x
−
2
y
=
7
Answer:
This isn't middle school
Step-by-step explanation:
Answer:
a. 8935.5 seconds
b 3600 seconds
c. not sure about this one
Step-by-step explanation:
Answer:
Subtract 26 from both sides 3x+26=2x+18 3x+26-26 = 2x + 18 -26
