A number decreased by 4 equals -12. What is the number? _____
1 answer:
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Answer:
Approximately 3.5 feet - Option B
Step-by-step explanation:
Imagine that you have this walkway around the garden, with dimensions 30 by 20 feet. This walkway has a difference of x feet between it's length, and say the dimension 30 feet. In fact it has a difference of x along both dimensions - on either ends. Therefore, the increases length and width should be 30 + 2x, and 20 + 2x, which is with respect to an increases area of 1,000 square feet.
( 30 + 2x ) ( 20 + 2x ) = 1000 - Expand "( 30 + 2x )
( 20 + 2x )"
600 + 100x + 4 = 1000 - Subtract 1000 on either side, making on side = 0
4 + 100x - 400 = 0 - Take the "quadratic equation formula"
( Quadratic Equation is as follows ) - ,
,
There can't be a negative width of the walkway, hence our solution should be ( in exact terms ) . The approximated value however is 3.5081...or approximately 3.5 feet.