13x - 4 < 12(x-1)
13x - 4 < 12x - 12
13x - 12x < -12 + 4
x < -8
x > 8
x is greater than 8
Answer:
(2, -1)
Step-by-step explanation:
because that's where the lines intersect
Answer:
105km
Step-by-step explanation:
1/7=15/x
So x=7*15
x=105
Answer:
Since the focus is at (-6,-11) and the directrix is at y=9:
The vertex is halfway between the focus and the directrix, so the vertex is at (-6,-1). (Draw this on graph paper if that doesn't make sense.)
The general form (conics form) of a parabola: 4p(y-k)=(x-h)^2 (vertex is (h,k) and "p" is the distance between the focus and vertex (or between vertex and directrix)).
(h,k) = (-6,-1)
p = 10 (distance between focus and vertex), so 4p = 40.
Therefore:
40(y+1)=(x+6)^2
Or if you need to rearrange to "vertex form": y=(1/40)(x+6)^2 - 1
Step-by-step explanation:
D.
first, eliminate B and C, because the highest degree in these two equation is 3, a 3-degree equation has 3 roots, not 4.
between A and D, A has the roots 0, 0, 7, and -7, all real roots.
D can be factored into (x²-49)(x²+1)=0
x²=49 or x²=-1
x=7 or -7, x=i or -i two real roots, two unreal roots
for the second equation:
first, find the first term by using the formula:
the nth term=the first term + (n-1)*difference
you are given the 13th term and d=3.7
a13=a1+(13-1)d
1.9=a1+12*3.7
a1=-42.5
the sum of the first 13 terms is S=(a1+a13)*(13/2)=(-42.5+1.9)*6.5=-263.9
