Because you can only add and subtract radicals with the same radicand,
you get 2
that is the simplified answer but if you want it in decimals, 2.022 is what you get.
x = number of 1-cent stamps
y = number of 8-cent stamps
z = number of 12-cent stamps
We have 31 stamps all together, so x+y+z = 31.
"I have 4 more 1-cent stamps than 8-cent stamps" means we have the equation x = y+8. Whatever y is, add 8 to it to get x. Solve for y to get y = x-8.
You also have "twice as many one cent stamps as 12 cent stamps", so x = 2z. Solving for z gets you z = 0.5x
-------------
x+y+z = 31
x+x-8+z = 31 ... y replaced with x-8
x+x-8+0.5x = 31 ... plug in z = 0.5x
2.5x-8 = 31
2.5x = 31+8
2.5x = 39
x = 39/2.5
x = 15.6
Your teacher made a typo somewhere because we should get a positive whole number result for x (since x is a count of how many 1-cent stamps we have).
32 in. because 2.5 feet is only 30 in
Answer:
b
Step-by-step explanation:
The equation:
3
x
2
−
5
x
−
12
=
0
is in the form:
a
x
2
+
b
x
+
c
=
0
with
a
=
3
,
b
=
−
5
,
c
=
−
12
The roots are given by the quadratic formula:
x
=
−
b
±
√
b
2
−
4
a
c
2
a
x
=
5
±
√
(
−
5
)
2
−
4
(
3
)
(
−
12
)
2
(
3
)
x
=
5
±
√
25
+
144
6
x
=
5
±
√
169
6
x
=
5
±
13
6
That is:
x
=
5
+
13
6
=
18
6
=
3
or
x
=
5
−
13
6
=
−
8
6
=
−
4
3
I think it might be C or B I'm honestly not 100% sure.
