7 + 8(3² -2) PLEASE SHOW ALL THE STEPS!
1 answer:
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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
Let's start with what we know:
Smaller canvas:
Length (
) = 3ft
Width (
) = 5ft
Larger canvas:
Length (
) = ?
Width (
) = 10ft
Since these are similar rectangles, we can cross-multiply to calculate the missing length. Here's that formula:
So let's plug it all in from above:
Now we cross multiply by multiplying the top-left by the bottom-right and vice versa:
Now divide each side by 5 to isolate
The 5s on the right cancel out, leaving us with:
So the length of the larger canvas is 6 ft
Smaller canvas:
Length (
Width (
Larger canvas:
Length (
Width (
Since these are similar rectangles, we can cross-multiply to calculate the missing length. Here's that formula:
So let's plug it all in from above:
Now we cross multiply by multiplying the top-left by the bottom-right and vice versa:
Now divide each side by 5 to isolate
The 5s on the right cancel out, leaving us with:
So the length of the larger canvas is 6 ft