Answer:
Step-by-step explanation:
By using the Pythagorean theorem:
b^2+3^2=5^2
b^2+9=25
b=sqrt (25-9)
b=sqrt(16)
b=4
=> 4^2+7^2=c^2
16+49=c^2
65=c^2
=>c=sqrt(65)
c = (approximately) 8
Let x be your first alloy
2/5x+7/10(30-x)=1/2(30)
4x+210-7x=150
3x=60
x=20
So, you need 20 lbs of the first alloy, and 10 parts of the second to make 30 lbs of half iron and half silver alloy!
5.67 (performed on a calculator)
Answer: Side QR
Step-by-step explanation: The sum of a triangle internal angles is 180°. So to determine the angles, we calculate x:
5x - 27 +4x - 7 + 3x + 10 = 180
12x = 204
x = 17
With x, solve for the angles:
m∠P = 5(17) - 27 = 58
m∠Q = 4(17) - 7 = 61
m∠R = 3(17) + 10 = 61
The relationship between angles and sides in any triangle:
- the largest angle is opposite the largest side;
- the middle angle is opposite to the middle-sized side;
- the shortest angle and side are opposite to each other;
So, the shortest side of PQR is the side opposite to the shortest angle.
The shortest angle is m∠P = 58°. Therefore, the shortest side is QR