Answer: its x = 3
Step-by-step explanation:
The maximum or minimum of a quadratic function occurs at
x
=
−
b
2
a
. If
a
is negative, the maximum value of the function is
f
(
−
b
2
a
)
. If
a
is positive, the minimum value of the function is
f
(
−
b
2
a
)
.
f
min
x
=
a
x
2
+
b
x
+
c
occurs at
x
=
−
b
2
a
Find the value of
x
equal to
−
b
2
a
.
x
=
−
b
2
a
Substitute in the values of
a
and
b
.
x
=
−
−
12
2
(
2
)
Remove parentheses.
x
=
−
−
12
2
(
2
)
Simplify
−
−
12
2
(
2
)
.
Tap for more steps...
x
=
3
The maximum or minimum of a quadratic function occurs at
x
=
−
b
2
a
. If
a
is negative, the maximum value of the function is
f
(
−
b
2
a
)
. If
a
is positive, the minimum value of the function is
f
(
−
b
2
a
)
.
f
min
x
=
a
x
2
+
b
x
+
c
occurs at
x
=
−
b
2
a
Find the value of
x
equal to
−
b
2
a
.
x
=
−
b
2
a
Substitute in the values of
a
and
b
.
x
=
−
−
12
2
(
2
)
Remove parentheses.
x
=
−
−
12
2
(
2
)
Simplify
−
−
12
2
(
2
)
.
Tap for more steps...
x
=
3
Cancel out the terms from one side first then do it for the other one. 4 example make x and individual by multiply the other side by 9 the evaluate. do the same for y
1. Eyeballing the data, the best fit will be pretty close to a line between the leftmost point and the rightmost point.
We estimate those points as (4,220) and (28,470)
The point point form for a line joining (a,b) and (c,d) is
(c-a)(y-b) = (d-b)(x-a)
(28 - 4)(y - 220) = (470 - 220)(x - 4)
24(y - 220) = 250(x-4)
24y - 5280 = 250x - 1000
24y = 250 x + 4280
y = (250/24) x+ (4280/24)
Approximately that's,
y = 10.4 x + 178
Answer: 4th choice, 10.4x + 180
2. For 48 wheelbarrows,
y = 10.4(48)+180 = 679.2
Answer: 679.2 liters of sand