Answer:
86
Step-by-step explanation:
Answer: Option C) Raj forgot the negative when substituting -15+9x for y.
Solution:
(1) 9x-y=15
(2) 2x+8y=28
Isolating y in the first equation. Subtracting 9x both sides of the equation:
(1) 9x-y-9x=15-9x
Subtracting:
(1) -y=15-9x
Multiplying both sides of the equation by -1:
(1) (-1)(-y)=(-1)(15-9x)
(1) y=-15+9x
Then Raj found the value of y. It's not option D.
Substitutng y by -15+9x in the second equation:
(2) 2x+8(-15+9x)=28
Then option C) is the answer: Raj forgot the negative when substituting -15+9x for y.
Eliminating the parentheses applying the distributive property in the multiplication:
(2) 2x-120+72x=28
Adding similar terms:
(2) 74x-120=28
Solving for x. Adding 120 both sides of the equation:
(2) 74x-120+120=28+120
Adding:
(2) 74x=148
Dividing both sides of the equation by 74:
(2) 74x/74=148/74
Dividing:
(2) x=2
Solving for y: Replacing x by 2 in the first equation:
(1) y=-15+9x
(1) y=-15+9(2)
Multiplying:
(1) y=-15+18
Subtracting:
(1) y=3
Equation 1 for tickets sold:
$35x + $25y = $10,250
Equation 2 for quantity (number #) of tickets sold:
x + y = 350
Use substitution method:
y = 350 - x
35x + 25 (350 - x) = $10,250
35x + $8750 - 25x = $10,250
10x + $8750 = $10,250
- $8,750 -$8,750
10x = 1,500
x = 150
y = 350 - 150
y = 200
Check the answers:
$35 (150) + $25 (200) =
$5,250 + $5,000 = $10,250
A balanced equation in math means both sides on the equal side are both balanced meaning they’re both the same
we know that
Each meter of ribbon cost 
so
by proportion
Find the cost of 
meters of ribbon
therefore
<u>the answer is</u>
The ribbon cost 
