The large triangle is an isosceles since both angles at the base each equal 42°.
In an isosceles triangle the altitude z is at the same time median , then it bisects the opposite side in the middle . So w = 120/2 = 60
Now let's calculate z:
tan 42° = (opposite side) / (adjacent side) = z/60
tan 42° = 0.9,
0.9 = z/60 and z = 54
It's not perfectly clear, but you seem to be saying that each week, the
pond becomes 3% deeper than it was THE PREVIOUS WEEK.
If I'm reading that correctly, then the pond is 10-ft deep when the rainy
season begins, and after 'x' weeks later, the depth is
D = 10 (1.03)^x feet.
After 8 weeks, the depth is D = 10 (1.03)⁸ = 12.67 feet .
rounded to the nearest foot, D = 13 ft.
This is a system of equations. We solve it by setting it up so that when we add the two equations together, one of the variables will cancel out. We can do this by multiplying the bottom equation by 3. This will make our system of equations equal:
3a + b + 225
-3a + 3b = 75
Now we add these two equations together, because the a terms will cancel out.
4b = 300.
We can find what b is by dividing both sides by 4.
b = 75
Next, we plug in b in one of the equations and solve for a. You can use either equation, but I will use the second.
75 - a = 25
Subtract 25 from both sides and add a to both sides:
a = 50
So, the first option is correct. A = 50 and b = 75.
I think they are at 7:10 pm
Exponential laws
x^-m=1/(x^m)
and (x^m)(x^n)=x^(m+n)
so
(3^-4)(3^2)=
3^(-4+2)=
3^-2=
1/(3^2)=
1/9
the answer is A
