Answer:
-4
Step-by-step explanation:
trust me im smart
Solve for the area of the circular region first:
A = pi*r^2
A = pi*(30 mi)^2
A = 2827.43 mi^2
Density = 70000 people/2827.43 mi^2
Density = 24.76 = 25 people/mi^2 <--ANSWER Plz vote brainnliest
Answer: x=75
Explanation:
x+10+x+20=180
combine like terms
2x+30=180
subtract 30 from each side
2x=150
divide each side by 2
x=75
"31-inch piece of steel is cut into three pieces"
Call the pieces a,b,c
a + b + c = 31
"second piece is twice as long as the first piece"
b = 2a
"third piece is one inch more than seven times the length of the first piece"
c = 1 + 7a
Ok, we have our equations, let's substitute the second and third into the first.
a + 2a + 1 + 7a = 31
10a + 1 = 31
10a = 30
a = 30/10 = 3
b = 2a = 6
c = 1 + 7a = 22
Check: 3 + 6 + 22 = 31, good
Answer: 3 inches, 6 inches, 22 inches
C is correct,
A is wrong as it halves both the angles and lengths by two which is the same as what she did in the first place so it cannot be correct.
B is also wrong for a similar reason, a triangle cannot have less than 180 degrees, which is impossible as the angles just change naturally which is why all triangles must have 180 degrees, which is the reason she is wrong in the first place.
And D is just incorrect, if she wanted to have shorter sides she should have only decreased all the lengths as it the the ratio of angles that determine the shape of a triangle while the sum of all angles is 180 degrees.