Answer:
Step-by-step explanation:
"y" is geometric mean
y² = 13 × 2
<em>y </em>= √26 <em>≈</em><em> 5.1</em>
x² = 26 + 4 = 30
<em>x</em> = √30 <em>≈</em><em> 5.5</em>
z² = 15² - 30 = 195
<em>z </em>= √195 <em>≈</em><em> 14.0</em>
Let, the number of student = x
Fraction of boys = 1 - 2/5 = 3/5
So, it would be: x * 3/5 = 1482
x = 1482*5 / 3
x = 7410/3
x = 2470
Thus, There are total 2470 students
Hope this helps!
Ah okay so in differential equations you usually want the top variable isolated. To do this, multiply by dt and 2u and you get

Now just integrate both sides. The integral of 2u with respect to u is u². The integral of (2t + sec²(t) with respect to t is t² + ∫sec²(t)dt. The last part is just tan(x) because d/dt(tan(t)) is sec²(t) so just integrating gets us back. Now we have

Where c and k are arbitrary constants. Subtracting c from k and you get

Where b is another constant. To find b, just plug in u(0) = -1 where u is -1 and t is 0. This becomes

tan(0) is 0 so b = 1. Take the plus or minus square root on both sides and you finally get

But Brainly didn't let me do but juat remember there is a plus or minus square root on the left.
The inttrest rate would be 4