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
The answer to this is 0.2725
Answer:
58.5
Step-by-step explanation:
This expression should be simplified using order of operations. According to order of operations or PEMDAS, complete any numbers in parenthesis then any exponents, multiplication, division, additions and subtraction moving left to right through each operation.
Begin with Parenthesis.
(7+3-4*9) - Multiply first
(7+3-36) - Then add/subtract left to right
10 - 36 = -26
Replace -26 where the parenthesis were in the original expression.
9/4 (-26)
234/4
58.5
