so, start floor = x
x + 7 - 9 - 4 + 8 - 2 = 14
x = 14
the elevator started on the 14th floor.
to verify: 14 + 7 = 21 - 9 = 12 - 4 = 8 + 8 = 16 - 2 = 14
Answer:
On the 7th day.
Step-by-step explanation:
The mold doubles, so on the 7th day, the mold would be half-there.
I used the 8th day's description to figure this out.
Step-by-step explanation:
area of trapezoid=(a+b)×h divided by 2
=(9+19)×4 divided by2
=28×4 divided by2
=112 divided by 2
=56m square
Simplifying
7x + 2y = 16
Solving
7x + 2y = 16
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-2y' to each side of the equation.
7x + 2y + -2y = 16 + -2y
Combine like terms: 2y + -2y = 0
7x + 0 = 16 + -2y
7x = 16 + -2y
Divide each side by '7'.
x = 2.285714286 + -0.2857142857y
Simplifying
x = 2.285714286 + -0.2857142857y