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:
y = -2x + 5
Step-by-step explanation:
y=
-3
Slope of this line m₁ = 1/2
Slope of the line perpendicular to this line = m₂
m₁ *m₂ = -1
m₂ = -1 *2/1 = -2
Slope = -2; (1,3)
y- y₁ = m(x-x₁)
y - 3 = -2(x - 1)
y - 3 = -2x + 2
y = -2x +2 +3
y = -2x + 5
Using the quadratic formula works but if you know there are 2 answers (highest power of problem tells you how many solutions) then
10x^2 = 5x
So either x = 0, giving 0=0. Or divide by 5x
2x = 1
x = 0.5
Answer:
625
Step-by-step explanation:
t= d/s
2500/4
40.25 you add everything together then multiply by .6