Answer:
92 attendees had activity cards
Step-by-step explanation:
Let x be the number of students with activity cards. Then 130-x is the number without, and the total revenue is ...
7x +10(130 -x) = 1024
7x +1300 -10x = 1024 . . . . eliminate parentheses
-3x = -276 . . . . . . . . . . . . . collect terms; subtract 1300
x = 92 . . . . . . divide by 3
92 students with activity cards attended the dance.
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<em>Comment on the solution</em>
Often, you will see such a problem solved using two equations. For example, they might be ...
Let 'a' represent the number with an activity card; 'w' the number without. Then ...
- a+w = 130 . . . . the total number of students
- 7a +10w = 1024 . . . . the revenue from ticket sales
The problem statement asks for the value of 'a', so you want to eliminate w from these equations. You can do that using substitution. Using the first equation to write an expression for w, you have ...
w = 130-a
and making the substitution into the second equation gives ...
7a +10(130 -a) = 1024
This should look a lot like the equation we used above. There, we skipped the extra variable and went straight to the single equation we needed to solve.
Answer:
z = (-b + 17)/(a+4)
Step-by-step explanation:
If in terms of a and b, then
az - 17 = -4z - b
z(a-4) = -b+17
z = (-b + 17)/(a+4)
Answer:
(3x - 2)(x - 5)
Step-by-step explanation:
3x² - 17a + 10
(3x - 2)(x - 5)
3x · x = 3x²
3x · -5 = -15x
-2 · x = -2x
-2 · -5 = 10
3 squares = 4 circles, so (number of squares)/(number of circles) = 3/4.
3/4 = 12/16
:::::
4 squares = 2 circles, so (number of squares)/(number of circles) = 4/2.
4/2 = 2/1
:::::
2 squares = 5 circles, so (number of squares)/(number of circles) = 2/5.
2/5 = 4/10
To tessellate a surface using a regular polygon, the interior angle must be a sub-multiple (i.e. factor) of 360 degrees to cover completely the surface.
For a regular three-sided polygon, the interior angle is (180-360/3)=60 °
Since 6*60=360, so a regular three-sided polygon (equilateral triangle) tessellates.
For a regular four-sided polygon, the interior angle is (180-360/4)=90 °
Since 4*90=360, so a regular four-sided polygon (square) tessellates.
For a regular five-sided polygon, the interior angle is (180-360/5)=108 °
Since 360/108=3.33... (not an integer), so a regular five-sided polygon (pentagon) does NOT tessellate.
For a regular six-sided polygon, the interior angle is (180-360/6)=120 °
Since 3*120=360, so a regular six-sided polygon (hexagon) tessellates.
