It lands on floor 5.
10-9+19-3-12
1+19-3-12
20-3-12
17-12
5
Answer: Variant C
Step-by-step explanation:
f(x) = 3x^2 − 4
For finding f(-2) just replace x with - 2 like this:
f(-2)=3*((-2))^2-4=3*4-4=12-4=8
<u>Let's solve this problem step-by-step</u>
<u>Let's set</u>:
2x + 6y = 36 -- equation 1
x + 4y = 20 -- equation 2
(equation 2) * 2
2x + 8y = 40 -- equation 3
(equation 3) - (equation 1)
2y = 4
y = 2 -- equation 4
Plug (equation 4)'s value of y into (equation 2)
x + 4(2) = 20
x = 20 - 8
x = 12
<u>Thus x = 12 and y = 2</u>
<u>Let's check, by substituting these values</u>

<u>Answer: x = 12 and y = 2</u>
Hope that helps!
2 tens, and 8 ones. I say this because 20 = 10 + 10 so, two tens. 8= 1+1+1+1+1+1+1+1 so, eight ones.
To convert a fraction to a decimal, divide the numerator by the denominator (divide the top by the bottom)