Step-by-step explanation:
The upstream speed is S / t₁, and the downstream speed is S / t₂.
If we say f is the speed of the fish in calm water, and r is the speed of the river, then:
f − r = S / t₁
f + r = S / t₂
If we say T is the time it takes to cross the river, then the speed perpendicular to the river is ℓ/T, the speed parallel to the river is r, and the overall speed is f.
Using Pythagorean theorem:
f² = (ℓ/T)² + r²
f² − r² = (ℓ/T)²
(f − r) (f + r) = (ℓ/T)²
(S / t₁) (S / t₂) = (ℓ/T)²
S² / (t₁ t₂) = (ℓ/T)²
(t₁ t₂) / S² = (T/ℓ)²
√(t₁ t₂) / S = T/ℓ
T = ℓ√(t₁ t₂) / S
Answer:
A=34, G=31
Step-by-step explanation:
G=A-3
2G+A=99
plug in for g 2(A-3)+A=99
distribute 2 A-3+A=99
combine like terms 3A-3=99
solve for a 3A=102 A=34
plug in a solve for g G=34-3 G=31
Answer:
270 yds squared
Step-by-step explanation:
You need to area of each of the shapes that make up the triangular prism. So, the side triangles, the back rectangle, the bottom rectangle and the top rectangle.
Side triangle (1x): base*height/2
12*5/2
60/2
30 yds, 60 yds for both sides.
Back rectangle: length*width
5*7
35 yds
Bottom Rectangle: length*width
7*12
84 yds
Top rectangle: length*width
7*13
91 yds.
To get the final answer, you add the surface areas together to get the final amount of yards: 30+30+35+84+91= 270 yds squared. Hope this helps.
Answer:
x = 5
Step-by-step explanation:
3x - 2 = x + 8
Subtract x from each side
3x-x - 2 = x-x + 8
2x -2 = 8
Add 2 to each side
2x-2+2 = 8+2
2x = 10
Divide each side by 2
2x/2 =10/2
x = 5
