Step-by-step explanation:
3x + 5y = 21 * (-4) •••••• -12x -20y = -84 (a)
4x - 2y = -24 * (3) •••••• 12x -6y = -72 (b)
(a) + (b)
-26y = -156
y = 6
3x + 5 * 6 = 21
3x = 21 - 30
3x = -9
x = -3
Answer:
Stem-and-leaf. You can use a stem-and-leaf plot to find the mean, median and mode of a set of data.
Answer:
75%
Step-by-step explanation:
257 is a whole number, interger, and a rational number.
Answer:
It is a perfect square. Explanation below.
Explanation:
Perfect squares are of the form
(
a
+
b
)
2
=
a
2
+
2
a
b
+
b
2
. In polynomials of x, the a-term is always x.(
(
x
+
c
)
2
=
x
2
+
2
c
x
+
c
2
)
x
2
+
8
x
+
16
is the given trinomial. Notice that the first term and the constant are both perfect squares:
x
2
is the square of x and 16 is the square of 4.
So we find that the first and last terms correspond to our expansion. Now we must check if the middle term,
8
x
is of the form
2
c
x
.
The middle term is twice the constant times x, so it is
2
×
4
×
x
=
8
x
.
Okay, we found out that the trinomial is of the form
(
x
+
c
)
2
, where
x
=
x
and
c
=
4
.
Let us rewrite it as
x
2
+
8
x
+
16
=
(
x
+
4
)
2
. Now we can say it is a perfect square, as it is the square of
(
x
+
4
)
.
