The answer to this question is:
y = -2x - 1
Gm, it’s almost night for me
Let x = the number of hours Eva needs to complete the job
and y = the number of hours Emily needs to complete the job
x = 6
1/x + 1/y = 1/4
(The amount of work Eva does in 1 hr + the amount of work Emily does in 1 hr should equal 1/4 of the total work)
1/6 + 1/y = 1/4
1/y = 1/12
y = 12 hours
Emily would take 12 hours to do it by herself.
Answer: A. contains mirrors that reflect the object
Step-by-step explanation:
A periscope contains mirrors in it that are on opposite sides and are arranged in a 45° angle to each other. It works by light striking the first mirror which cause its to reflect it at a 45° angle to the next mirror.
Depending on the length of the periscope, this continues until the last mirror reflects the incoming light to the eyes of the person using the periscope thereby allowing them to see objects hidden behind or under a barrier.
Answer:
A product of factors is zero if and only if one or more of the factors is zero. That is, if ab = 0, then either a = 0 or b = 0 (or both).
Hence (x+3)(x+12) = 0 only if (x+3) = 0 or (x+12) = 0 or both. (x+3) = 0 when x = 3.(x+12) = 0 when x = 12.
Hence the values of x that make (x+3)(x+12) = 0 are x = 3 and x = 12.
