Answer:
a= 22.5
b= 37.5
Step-by-step explanation:
<u>In</u><u> </u><u>△</u><u>BCD</u><u>:</u>
Applying Pythagoras' Theorem,
a² +30²= b²
a² +900= b² -----(1)
<u>In</u><u> </u><u>△</u><u>ABC</u><u>:</u>
Applying Pythagoras' Theorem,
b² +50²= (40 +a)² -----(2)
Substitute (1) into (2):
a² +900 +50²= 40² +2(40)(a) +a²<em> </em><em> </em><em> </em><em> </em><em> </em><em>(</em><em>expand</em><em> </em><em>bracket</em><em>)</em>
a² +900 +2500= 1600 +80a +a²
a² +3400= a² +80a +1600 <em>(</em><em>simplify</em><em>)</em>
a² +3400 -a² -80a -1600= 0 <em>(</em><em>bring</em><em> </em><em>everything</em><em> </em><em>to</em><em> </em><em>1</em><em> </em><em>side</em><em>)</em>
-80a +1800= 0
80a= 1800 <em>(</em><em>+</em><em>8</em><em>0</em><em> </em><em>on</em><em> </em><em>both</em><em> </em><em>sides</em><em>)</em>
a= 1800 ÷80
a= 22.5
Subst. a= 22.5 into (1):
22.5² +900= b²
b²= 506.25 +900
b²= 1406.25
b= √1406.25 <em>(</em><em>square</em><em> </em><em>root</em><em> </em><em>both</em><em> </em><em>sides</em><em>)</em>
b= 37.5 <em>(</em><em>reject</em><em> </em><em>negative</em><em> </em><em>value</em><em> </em><em>since</em><em> </em><em>b</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>length</em><em>)</em>
☆(a +b)²= a² +2ab +b²
The selling price will be $232 if he applies a 45% markup.
Step-by-step explanation:
Cost of each stereo = $160
Mark up = 45%
Amount of mark up =
Amount of mark up =
Selling price = Cost of stereo + mark up
Selling price = 160 + 72 = $232
The selling price will be $232 if he applies a 45% markup.
Keywords: addition, markup
Learn more about addition at:
#LearnwithBrainly
9514 1404 393
Answer:
(a) 22 is not the correct value of h
(b) 164 ft²
(c) $2009
Step-by-step explanation:
(a) Apparently, the formula ...
A = 1/2bh
was used. We recognize the base of the triangle is 16 feet, so apparently the formula was used with h=22.
22 is the side length, not the perpendicular distance from the base to the opposite vertex.
The computed value is not the area because 22 is not the height.
__
(b) Given three side lengths, an appropriate formula is Heron's formula:
s = (a+b+c)/2 and A = √(s(s-a)(s-b)(s-c))
Here, we have ...
s = (22 +22 +16)/2 = 30 and A = √(30(8)(8)(14) = 16√105 ≈ 163.95
The area is about 164 square feet.
__
(c) At $12.25 per square foot, the cost of materials will be ...
(164 ft²)($12.25/ft²) = $2009
