Answer:
68 aliens
Step-by-step explanation:
Take the fraction of aliens that had 3 eyes and multiply by the number of aliens
17 / 40 * 160 =
17 * 160/40
17 *4
68
Ok, I'm going to start off saying there is probably an easier way of doing this that's right in front of my face, but I can't see it so I'm going to use Heron's formula, which is A=√[s(s-a)(s-b)(s-c)] where A is the area, s is the semiperimeter (half of the perimeter), and a, b, and c are the side lengths.
Substitute the known values into the formula:
x√10=√{[(x+x+1+2x-1)/2][({x+x+1+2x-1}/2)-x][({x+x+1+2x-1}/2)-(x+1)][({x+x+1+2x-1}/2)-(2x-1)]}
Simplify:
<span>x√10=√{[4x/2][(4x/2)-x][(4x/2)-(x+1)][(4x/2)-(2x-1)]}</span>
<span>x√10=√[2x(2x-x)(2x-x-1)(2x-2x+1)]</span>
<span>x√10=√[2x(x)(x-1)(1)]</span>
<span>x√10=√[2x²(x-1)]</span>
<span>x√10=√(2x³-2x²)</span>
<span>10x²=2x³-2x²</span>
<span>2x³-12x²=0</span>
<span>2x²(x-6)=0</span>
<span>2x²=0 or x-6=0</span>
<span>x=0 or x=6</span>
<span>Therefore, x=6 (you can't have a length of 0).</span>
Answer:
1.
Step-by-step explanation:
When x is 0, the point will lie on the x-axis, so we need to find how many times this happens.
There's only 1 0, so the answer is 1.
Number of seats = 42
Seats per row x row = 1302
s x r = 1302
rows + 11 = seats per row
r + 11 = s
s x r = 1302
(r + 11) x r = 1302
r^2 + 11r = 1302
r^2 + 11r - 1302 = 0
(r + 42) x (r - 31) = 0
r = -43 or 31
Cannot have negative rows so the number of rows is 31, and the number of seats per row is 31 + 11 = 42
Check: 31 x 42 = 1302 :)