Answer:
48
Step-by-step explanation:
{-2x-5y=13
<u>{2x-5y=17 </u>(+)
<em /> -2x+2x-5y-5y=13+17
-10y=30 /:(-10)
y=-3
2x-5y=17
2x-5*(-3)=17
2x+15=17
2x=2
x=1
<em>Solution: (1; -3)</em>
14: k^-3/k^4= 1/k^7
15: answer : 1/3²
16: n^-4
17: f-g^4 = 3-(-5)^4 = -622
18: (x^5-y^2)²+x³ =
(2^5-8^2)²+2³ =1032
19: m²-n³
6²-2³ = 36-8=28
20 : 2²×3²×5³= 4500
4500/10 = 450 islands
2.3 yard
Divide the length (84) by 36 inches (one yard)
956.73
0.3% = 0.003
1-0.003 = 0.997
49/6 = 8 r1 (use 8 because decay is not continuous)
0.997^8 = 0.97625...
0.97625... x 980 ≈ 956.73