Combine like terms. -2y+y=-y. The equation is now -y-3=6. You need to get the y by itself so add 3 to both sides. The equation is now -y=9. You are solving for y so divide both sides by -1. The equation will be y=-9. The answer is y=-9. Hope this helps! ;)
Answer:
y = x² + x - 12
Step-by-step explanation:
Given the solutions are x = - 4 and x = 3, then the factors are
x(x - (- 4)) and (x - 3), that is (x + 4) and (x - 3)
The equation is then the product of the factors
y = (x + 4)(x - 3) ← expand using FOIL
= x² - 3x + 4x - 12
= x² + x - 12 ← in standard form
So you are seeing how much time it'll take so you solve for "t", the time.
<span>So you take the formula A=Pe^(rt) </span>
<span>A=2000 because it's the end value </span>
<span>P=20 because it's the starting value </span>
<span>r=.85 since 85%=.85 and .85 is the rate </span>
<span>Plug the values in and you get 2000=20e^(.85t) </span>
<span>What you do is you divide by 20 so you get 100=e^(.85t) </span>
<span>Take the natural logarithm of both sides 'cause of e and a natural log is written as ln so you get </span>
<span>ln 100=.85t ln e and because you can use the power rule you end up with .85t ln e and </span>
<span>ln e=1 so you have ln 100 = .85t so you divide by .85 so (ln 100)/.85=t and t=5.4178472776331 </span>
<span>hours </span>
<span>3. Exponential decay: </span>
<span>A= Pe^(rt) </span>
<span>where </span>
<span>A is the final amount </span>
<span>P is the initial value </span>
<span>r is rate of decay </span>
<span>t is time (years) </span>
<span>Let's say x is the initial amount then (1/2)x=xe^(32r) </span>
<span>I used x because the value isn't given but anyway division by x would give you 1/2=e^(32r) </span>
<span>Take the ln of both sides so ln 1/2=32r ln e and then ln e=1 so ln 1/2=32r. </span>
<span>Divide both sides by 32 and you'd get (ln 1/2)/32=r and r= -0.021660849392498 </span>
<span>4. Another depreciation question. </span>
<span>Each year the item retains 88% of its last-year value. </span>
<span>Solve: 250,000(0.88)^x = 100,000 </span>
<span>0.88^x = 0.4 </span>
<span>x = [log0.4]/[log0.88] </span>
<span>x = 7.168 years </span>
Since you want to find out how many papers Mr. Elliot grades per minute, and he grades 50 every 20 minutes, divide 20 by 20, and you get 1 minute, and now divide 50 by 20, and you get 2.5 papers per minute. Mr. Elliot grades 2.5 papers per minute.
It gotta be c but it was kinda hard to c even when i close