First, make sure you convert both equations into standard form. Your two equations would be 2x+2y=38 and -x+y=3. Then multiply the bottom by 2. So your new equations would be 2x+2y=38 and -2x+2y=6. The x would cancel out and you would continue solving for y. y would equal 11 and then you would plug it back into an original equation. When you plug and solve for x, you would get x=8. So your answer would be (8,11)
Answer:
126
Step-by-step explanation:
the number of cargo cars is represented by the 35 part of the ratio , then
105 ÷ 35 = 3 ← value of 1 part of the ratio , then
passenger cars = 7 × 3 = 21
total cars = 105 + 21 = 126
After 1 hour, 360 g decays to 180 g.
After another hour (total 2 hours), 180 g decays to 90 g.
After another hour (total 3), 90 g decays to 45 g.
After one more (total 4), 45 g decays to 22.5 g.
More quickly, with a half-life of 1 hour, the 360 g of starting material decays to
(360 g) / 2⁴ = 22.5 g
In general, if the half-life is 1 hour, then after <em>n</em> hours, an initial amount <em>A</em> of this substance decays according to
<em>A</em> / 2<em>ⁿ</em>
Answer:
Step-by-step explanation:
Let the speed of plane is p and speed of the wind is w.
<u>Then we have:</u>
- 10*(p + w) = 1120 ⇒ p + w = 112
- 20*(p - w) = 1120 ⇒ p - w = 56
<u>Sum the two equations and solve for p:</u>
- p + w + p - w = 112 + 56
- 2p = 168
- p = 84
<u>Find w:</u>
- 84 + w = 112
- w = 112 - 84
- w = 28
Answer:
9
Explanation:
9 root 2 = root 81 x root 2 = root 162
Root 162 = 12.7279220614
9^2 + b^2 = 12.7279220614^2
81 + b^2 = 162
b^2 = 81
Root both
B = 9
