Answer:
13/28.
Step-by-step explanation:
(8/14 - 2/8) + 1/7
We can just remove the parentheses and simplify its contents:
= 4/7 - 1/4 + 1/7
= 4/7 + 1/7 - 1/4
= 5/7 - 1/4 The LCD of 7 and 4 is 28 so we have:
20/28 - 7/28
= 13/28.
This is the isosceles triangle. Therefore, the angles at the base are congruent.
We know that the sum of the measures of the angles in a triangle is 180°.
Therefore we have the equation:

<em>subtract 38 from both sides</em>
<em>divide both sides by 2</em>

<h3>Answer: x = 71.</h3>
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.
_____
<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:
225
Step-by-step explanation:
60 x 3 = 180 ($60 for each charity and there's 3 charities)
180 / (4/5) = 225 (if $180 is four fifths of his total just divide 180 by 4/5 to get the answer)