Answer:
1.8
Step-by-step explanation:
Solve for x
90
x
=
81
+
25
x
2
Subtract
25
x
2
from both sides of the equation.
90
x
−
25
x
2
=
81
Subtract
81
from both sides of the equation.
90
x
−
25
x
2
−
81
=
0
Factor the left side of the equation.
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−
(
5
x
−
9
)
2
=
0
Multiply each term in
−
(
5
x
−
9
)
2
=
0
by
−
1
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(
5
x
−
9
)
2
=
0
Set the
5
x
−
9
equal to
0
.
5
x
−
9
=
0
Solve for
x
.
Tap for more steps...
x
=
9
5
The result can be shown in multiple forms.
Exact Form:
x
=
9
5
Decimal Form:
x
=
1.8
Mixed Number Form:
x
=
1
4
5
Upgrade to
Answer:
15<em>y</em> = -28 <em>x</em> + 205.
Step-by-step explanation:
Slope intercept form of equation is <em>y = mx + c</em> where m is slope and c is the y intercept.
Now slope of line passing through points (-5, 23) and (10, -5):
Now equation of line:
<em> y = mx + c</em>
substituting the value of m in above expression,
Now, since the line is passing through the point (-5, 23) therefore, x = -5 and y = 23. By substituting these values in above equation,
So equation of line in slope intercept form:
Further solving,
15<em>y</em> = -28 <em>x</em> + 205.
Answer:
20 green pencils
Step-by-step explanation:
The difference between black and green "ratio units" is 7 -5 = 2. The difference between red and blue ratio units is 3 -2 = 1. The sum of those differences is 2 +1 = 3 ratio units, which represent 12 pencils. Then each ratio unit represents 12/3 = 4 pencils.
The 5 ratio units of green pencils represent 5·4 pencils = 20 green pencils.
_____
If you need an equation, you can use k as the constant of proportionality. Then the sum of differences described is ...
(7k -5k) + (3k -2k) = 12
3k = 12 . . . . simplify
k = 4 . . . . . . divide by 3
5k = 5·4 = 20 . . . . . number of green pencils
