SA=4pir^2
78.54km^2=SA
78.54=4pir^2
divide both sides by 4
19.635=pir^2
aprox pi=3.14 so divide both sides by 3.14
6.25318=r^2
sqrt both sides
2.50063=r
round
radius=2.5km
this question is flawed in that it gives the wrong units
answer is the option with 2.5 in it
2nd one
Answer: 128x^7dx-2240x^6dx+16800x^5dx-70000x^4dx+175000x^3dx-262500x^2dx+218750xdx-7812
Step-by-step explanation:
1) Expand : (2x-5\right)^7dxquad 128x^7dx-2240x^6dx+16800x^5dx-70000x^4dx+175000x^3dx-262500x^2dx
2) Distribute Parentheses
3) Apply your minus/plus rules
+(-a)= -a
128x^7dx-2240x^6dx+16800x^5dx-70000x^4dx+175000x^3dx-262500x^2dx+218750xdx-78125dx
Answer:
(0, 4) and (- 7, 0)
Step-by-step explanation:
Given
4x - 7y = - 28
To find the y- intercept, let x = 0 in the equation and solve for y
4(0) - 7y = - 28
- 7y = - 28 ( divide both sides by - 7 )
y = 4 ← y- intercept ⇒ (0, 4 )
To find the x- intercept let y = 0 in the equation and solve for x
4x - 7(0) = - 28
4x = - 28 ( divide both sides by 4 )
x = - 7 ← x- intercept ⇒ (- 7, 0 )
Answer:
5
Step-by-step explanation:
two negatives = a positive.
8 + 5 - 8 = 5