Answer:
Step-by-step explanation:
Rewrite
100
x
2
100
x
2
as
(
10
x
)
2
(
10
x
)
2
.
(
10
x
)
2
+
60
x
+
9
(
10
x
)
2
+
60
x
+
9
Rewrite
9
9
as
3
2
3
2
.
(
10
x
)
2
+
60
x
+
3
2
(
10
x
)
2
+
60
x
+
3
2
Check the middle term by multiplying
2
a
b
2
a
b
and compare this result with the middle term in the original expression.
2
a
b
=
2
⋅
(
10
x
)
⋅
3
2
a
b
=
2
⋅
(
10
x
)
⋅
3
Simplify.
2
a
b
=
60
x
2
a
b
=
60
x
Factor using the perfect square trinomial rule
a
2
+
2
a
b
+
b
2
=
(
a
+
b
)
2
a
2
+
2
a
b
+
b
2
=
(
a
+
b
)
2
, where
a
=
10
x
a
=
10
x
and
b
=
3
b
=
3
.
(
10
x
+
3
)
2
<span>Last
year, the average math SAT score for students at one school was 475. The
headmaster then introduced a new teaching method hoping to improve scores. This
year, the mean math SAT score for a sample of students was 491. The headmaster
concluded that the new teaching method produces higher SAT scores. The problem
with reporting results this way is voluntary response. The information of how
the teaching method isnot mentioned.</span>
Answer:
the answer is 9
Step-by-step explanation:
15/100 ?/60
multiply 60 by 15 to get 900, the divide 900 by 100 to get <em>9</em>
Round all of the numbers to the nearest 10 then solve the problem like normal
C. we multiply the equation by 3