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
Answer:
A function is a predefined formula that performs calculations using specific values in a particular order. All spreadsheet programs include common functions that can be used for quickly finding the sum, average, count, maximum value, and minimum value for a range of cells.
Step-by-step explanation:
Answer: 5 1/4
Step-by-step explanation:
Answer:
x = 7/5 or x = (-7)/5
Step-by-step explanation:
Solve for x over the real numbers:
49 - 25 x^2 = 0
Multiply both sides by -1:
25 x^2 - 49 = 0
x = (0 ± sqrt(0^2 - 4×25 (-49)))/(2×25) = ( ± sqrt(4900))/50:
x = sqrt(4900)/50 or x = (-sqrt(4900))/50
sqrt(4900) = sqrt(4×25×49) = sqrt(2^2×5^2×7^2) = 2×5×7 = 70:
x = 70/50 or x = (-70)/50
70/50 = 7/5:
x = 7/5 or x = (-70)/50
(-70)/50 = -7/5:
Answer:x = 7/5 or x = (-7)/5
Answer: D. 40
Step-by-step explanation:
1/2x=20
1/2x × 2=20 × 2 ⇔ multiplication property of equality
x=40
Hope this helps!! :)
Please let me know if you have any questions