Answer:
soln,
write the question
=9x^2+1-6x-2×9x^2+25+9x^2+25
=9x^2+1-6x-18x^2+25+9x^2+25
=9x^2-18x^2+9x^2+1+25+25-6x
=51-6x
if(3x+1)^2 mean that (3x+1)has power of 2 and u don't have to use the formula this is the answer
Step-by-step explanation:
it's just BODMAS method
Answer:
x = 
Step-by-step explanation:
We know that p(x) = 13. Thus, substitute 13 for the "p(x)" in the equation. Then, isolate x by subtracting both sides by 
:
Thus, x = .
Answer:
The 3rd option
Step-by-step explanation:
The pattern is every 2 hours is $15 so 4 hours would be equal to $30
Since 4 hours would equal 30 and we need 12 hours multiplying both numbers by 3 would get you the answer
4x3=12
30x3=90
Making it equal
The population Pa of insect A after t years is given by the equation
Pa = 1.3(1-0.038)^t
while the population Pb of insect B after t years is
Pb = 2.1(1-0.046)^t
We equate the above expressions to find the number of years t it will take the two populations to be equal:
Pa = Pb
1.3(1-0.038)^t = 2.1(1-0.046)^t
1.3(0.962)^t = 2.1(0.954)^t
These are the equations that can be used to determine how long it will be before the populations of the two species are equal.
We can now solve for t:
(0.962)^t / (0.954)^t = 2.1/1.3
(0.962/0.954)^t = 2.1/1.3
After taking the log of both sides of our equation, number of years t is
t = log (2.1/1.3) / log (0.962/0.954)
t = 57 years
Therefore, it will take 57 years for the population of insect A to equal the population of insect B.
\begin{gathered}\{\begin{array}{ccc}3x+5y=2&|\cdot(-3)\\9x+11y=14\end{array}\\\underline{+\{\begin{array}{ccc}-9x-15y=-6\\9x+11y=14\end{array}}\ \ |\text{add both sides of equations}\\.\ \ \ \ \ -4y=8\ \ \ |:(=4)\\.\ \ \ \ \ y=-2\\\\\text{substitute the value of y to the first equation}\\\\3x+5\cdot(-2)=2\\3x-10=2\ \ \ |+10\\3x=12\ \ \ |:3\\x=4\\\\Answer:\ x=4;\ y=-2\to(4;\ -2)\end{gathered}
{
3x+5y=2
9x+11y=14
∣⋅(−3)
−9x−15y=−6
9x+11y=14
add both sides of equations
. −4y=8 ∣:(=4)
. y=−2
substitute the value of y to the first equation
3x+5⋅(−2)=2
3x−10=2 ∣+10
3x=12 ∣:3
x=4
Answer: x=4; y=−2→(4; −2)
