We can factor this by using grouping. Take the leading coefficient and multiply it by the constant. In this case we get 5*-7 = -35.
Now we need 2 numbers that add to 2 and multiply to be -35. The numbers are -5 and 7.
So split the 2r into these two terms and group.
(5r^2 - 5r) + (7r - 7)
Factor both groups.
5r(r-1) + 7(r-1)
The factors of (r-1) can be added together to get the answer.
(r-1)(5r+7)
Answer:
f(x) = 2(x -3)² +5 or f(x) = 2x² -12x +23
Step-by-step explanation:
The equation of a quadratic is easily written in vertex form when the coordinates of the vertex are given. Here, the point one horizontal unit from the vertex is 2 vertical units higher, indicating the vertical scale factor is +2.
__
<h3>vertex form</h3>
The vertex form equation for a parabola is ...
f(x) = a(x -h)² +k . . . . . . vertex (h, k); vertical scale factor 'a'
<h3>equation</h3>
For vertex (h, k) = (3, 5) and vertical scale factor a=2, the vertex form equation of the parabola is ...
f(x) = 2(x -3)² +5 . . . . . vertex form equation
Expanded to standard form, this is ...
f(x) = 2(x² -6x +9) +5
f(x) = 2x² -12x +23 . . . . . standard form equation
Answer:
18.66 minutes or 18 minutes 39.6 seconds
Step-by-step explanation:
23 x .19 = 4.37
23 - 4.37 = 18.66 minutes
