When applying indirect proofs, we assume the negation of the conclusion is true, and show that this assumption would lead to nonsense, or contradiction.
In our case we assume a is not smaller than 7, that is we assume a≥7.
a≥7 then, multiplying both sides by 3:
3a≥21, then, adding both sides 7:
3a+7≥28,
which is a contradiction because 3a+7 is smaller than 28.
So our assumption is wrong, which means the opposite of it is correct.
Answer: assume a≥7
Answer:
Katie needs to pay $27.9.
Step-by-step explanation:
Given;
Cost of per foot = $2.25
Number of flowers in her yard = 12.4 square foot
We need to find how much she needs to pay.
Solution:
Now we know that;
So for 
= Cost for .
By using Unitary method we get;
Cost for = 
Hence Katie needs to pay $27.9.
Answers:
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Explanation:
Part (a)
Lines LN and PN have the point N in common. This is the intersection point.
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Part (b)
To name a plane, pick any three non-collinear points that are inside it. We cannot pick points H, J, K together because infinitely many planes pass through it. Imagine the piece of flat paper able to rotate around this axis (like a propeller). Having the points not all on the same line guarantees we form exactly one unique plane.
I'll pick the non-collinear points P, H and J to get the name Plane PHJ. Other answers are possible.
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Part (c)
Points H, J and K are collinear as they are on the same line. Pick either H or K to fill out the answer box. I'll go with point K
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Part (d)
Point P and line HK are coplanar. They exist in the same flat plane, or on the same sheet of flat paper together.
We can think of that flat plane as the ground level while something like point N is underground somewhere. So point N and anything on that ground plane wouldn't be coplanar.
Note: there are other possible names for line HK such as line JH or line JK. The order doesn't matter when it comes to naming lines.
Let the smaller number be x.
Given, the larger number is 7 times the smaller number.
So, the larger number = 7x.
Given, 3 times the larger number is 7 more than 4 times the smaller number.
So we can write the equation as,
Now we have to move 4x to the left side by subtracting 4x from both sides.
To get x, we will divide both sides by 17. We will get,
So the smaller number = 
The larger number = 
= 
So we have got the required numbers.
Smaller number = and larger number = .
Cost of items = $23.45
Tax = 8% of $23.45 = 0.08*23.45 = $1.88
Tip = 20% of $23.45 = 0.2*23.45 = $4.69
Total cost = 23.45 + 1.88 + 4.69 = 30.02
Answer: $30.02
