You need to get r alone:
r-3.9=-9.3 you need to add 3.9 to both sides:
r=-5.4 :)
Answer:
x = ± i 
Step-by-step explanation:
Given
3x² + 6 = 0 ( subtract 6 from both sides )
3x² = - 6 ( divide both sides by 3 )
x² = - 2 ( take the square root of both sides )
x = ± 
= ± 
= ± (
×
) →
= i
= ± i 
Answer:
-16/45
Step-by-step explanation:
(-8 x 2) / (9 x 5)
-16/45
Step-by-step explanation:
6 pizzas were eaten
Answer:
x = 4
Step-by-step explanation:
Since the triangle is right use Pythagoras' identity to solve for x
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
(x + 3)² + (4(x + 2))² = 25² ← expand parenthesis on left side
x² + 6x + 9 + 16(x+ 2)² = 625
x² + 6x + 9 + 16(x² + 4x + 4) = 625
x² + 6x + 9 + 16x² + 64x + 64 = 625 ← simplify left side
17x² + 70x + 73 = 625 ( subtract 625 from both sides )
17x² + 70x - 552 = 0 ← in standard form
with a = 17, b = 70, c = - 552
Using the quadratic formula to solve for x
x = ( - 70 ±
) / 34
= ( - 70 ±
) / 34
= - 70 ±
) / 34
= - 70 ± 206 ) / 34
x =
= - 8.1176....
or x =
= 4
However, x > 0 ⇒ x = 4
Hence
x + 3 = 4 + 3 = 7 and
4(4 + 2) = 24
The triangle is a 7- 24- 25 right triangle