Find each missing measure.
1 answer:
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Answer:
<em>Any width less than 3 feet</em>
Step-by-step explanation:
<u>Inequalities</u>
The garden plot will have an area of less than 18 square feet. If L is the length of the garden plot and W is the width, the area is calculated by:
A = L.W
The first condition can be written as follows:
LW < 18
The length should be 3 feet longer than the width, thus:
L = W + 3
Substituting in the inequality:
(W + 3)W < 18
Operating and rearranging:
Factoring:
(W-3)(W+6)<0
Since W must be positive, the only restriction comes from:
W - 3 < 0
Or, equivalently:
W < 3
Since:
L = W + 3
W = L - 3
This means:
L - 3 < 3
L < 6
The width should be less than 3 feet and therefore the length will be less than 6 feet.
If the measures are whole numbers, the possible dimensions of the garden plot are:
W = 1 ft, L = 4 ft
W = 2 ft, L = 5 ft
Another solution would be (for non-integer numbers):
W = 2.5 ft, L = 5.5 ft
There are infinitely many possible combinations for W and L as real numbers.
Answer:
.
Step-by-step explanation:
Let represent the mass (in pounds) of that
copper alloy required, such that the final mixture would contain
copper by mass.
Consider: if pounds of that
copper alloy is mixed with
pounds that
copper alloy, what would be the mass of copper in the mixture?
- Mass of copper in
pounds of that
copper alloy:
.
- Mass of copper in
pounds of that
copper alloy:
.
Therefore, the mixture would contain of copper.
The mass of that mixture would be . The mass fraction of copper in that mixture would be:
.
This ratio is supposed to be equal to . These two pieces of equations combine to give an equation about
:
.
.
Simplify and solve for :
.
.
.
Therefore, of that
alloy would be required.