Problem 11
<h3>Answer: h =
2A/b</h3>
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Explanation:
We need to get h by itself. To do so, we first multiply both sides by 2. Then we divide both sides by b
A = (1/2)*b*h
2A = b*h
b*h = 2A
h = 2A/b
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Problem 12
<h3>Answers:</h3>
- Equation: (n+2)/5 = 14
- Solution to that equation: n = 68
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Explanation:
The number n is increased by 2 to get n+2
Then we divide by 5 to get (n+2)/5
This is set equal to 14 to get the equation (n+2)/5 = 14
Solving the equation would look like this
(n+2)/5 = 14
n+2 = 5*14 .... multiply both sides by 5
n+2 = 70
n = 70-2 .... subtract 2 from both sides
n = 68
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Problem 13
<h3>Answer: Not a solution</h3>
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Explanation:
We'll replace every copy of x with -3 and simplify
-2x + 5 > 13
-2*(-3) + 5 > 13
6 + 5 > 13
11 > 13
The last inequality is false because 11 is not greater than 13. Since the last inequality is false, this makes the first inequality false when x = -3.
Therefore, x = -3 is not a solution.
A=P×(0.8)
A is the price after the markdown
P is the original price
0.8 is the multiplier because 1-(80/100)=0.8
80/100 is the same as 80%, which is the remaining value when 20% of the value of the item is deducted.
<u>EXPLANATION</u><u>:</u>
In ∆ ABC , ∠ABC = 40°
∠ACD is an exterior angle formed by extending BC to D
We know that
The exterior angle of a triangle formed by extending one side is equal to the sum of the opposite interior angles.
∠ACD = ∠CAB + ∠ABC
⇛50° = x° + 40°
⇛x° = 50°-40°
<h3>⇛x° = 10°</h3>
and
In ∆ ACD , AC = CD
⇛ ∠CDA = ∠CAD
Since the angles opposite to equal sides are equal.
Let ∠CDA = ∠CAD = A°
We know that
The sum of all angles in a triangle is 180°
In ∆ ACD,
∠CDA +∠CAD + ∠ACD = 180°
A°+A°+50° = 180°
⇛2A°+50° = 180°
⇛2A° = 180°-50°
⇛2A° = 130°
⇛A° = 130°/2
⇛A° = 65°
now,
∠CDA = ∠CAD = 65°
∠BAC + ∠CAD+y = 180°
Since angles in the same line
10°+65°+y = 180°
⇛75°+y =180°
⇛y = 180°-75°
<h3>⇛y = 105°</h3>
<u>Answer</u><u>:</u> Hence, the value of “x” & “y” will be 10° and 105° respectively.
I think they all are right are you not confident about one ...? I can explain it to you
