I am confused what is your question then i will tell you the answer.
Answer:
paper clips = $1.85
index cards = $3.95
Step-by-step explanation:
Mark
12 paper clips = x
10 index cards = y
$61.70 total
Janice
15 paper clips = x
7 index cards = y
$55.40 total
12x + 10y = 61.70
15x + 7y = 55.40
*** you want to cancel out one of the letters
(12x + 10y = 61.70) * -7
(15x + 7y = 55.40) * 10
-84x -70y = -431.9
150x + 70y = 554.0
150x + 70y = 554.0
-84x -70y = -431.9
66x + 0 = 122.1
66x = 122.1
x = 122.1 ÷ 66
x = 1.85
plug it back in
15(1.85) + 7y = 55.40
27.75 + 7y = 55.40
7y = 55.40 - 27.75
7y = 27.65
y = 27.65 ÷ 7
y = 3.95
<h3><em>Answer:</em></h3><h3><em></em></h3><h3><em>number of seats in theater = 1035</em></h3><h3><em></em></h3><h3><em>Step-by-step explanation:</em></h3><h3><em></em></h3><h3><em>Given in question as</em></h3><h3><em></em></h3><h3><em>Total number of rows of seat = 30</em></h3><h3><em></em></h3><h3><em>first row contain seat = 20</em></h3><h3><em></em></h3><h3><em>second row contain seat = 21 .. and so on</em></h3><h3><em></em></h3><h3><em>This is in arithmetic progression as 20 , 21 , 22 , 23 ...... so on</em></h3><h3><em></em></h3><h3><em>Then as number of terms N = 30 and first terms = a = 20</em></h3><h3><em></em></h3><h3><em>so we have to find Tn th terms</em></h3><h3><em></em></h3><h3><em>So, Tn th terms = first term + ( N -1 ) × d d= common difference i.e 1</em></h3><h3><em></em></h3><h3><em> Tn th terms = 20 + (30 - 1) × 1</em></h3><h3><em></em></h3><h3><em>Thus, Tn th terms = 49</em></h3><h3><em></em></h3><h3><em>i.e The number of seats in 30th row = 49</em></h3><h3><em></em></h3><h3><em>Now again Total number of seats in theater</em></h3><h3><em></em></h3><h3><em>sum of Nth terms = </em></h3><h3><em></em></h3><h3><em>so = </em></h3><h3><em></em></h3><h3><em> = 15 × 69 = 1035</em></h3><h3><em></em></h3><h3><em>Hence, Total number of seats in theater = 1035 Answer</em></h3>
Answer:
A, D, F.
Step-by-step explanation:
