Answer:
2 solutions
Step-by-step explanation:
x^4-6x^2-7=0
Replace x^2 by y
(x^2)^2-6x^2-7=0
y^2-6y-7=0
D=b^2-4ac= (-6)^2-4*1*(-7)= 36+28=64
sqrtD=8
y1=(-b-sqrtD)/2a=-2/2=-1
y2= (-b+sqrtD)/2a=14/2=7
x^2=-1(n0 roots) x^2=7 x=sqrt7 or x=-sqrt7
2 roots
It these triangles are similar, then the sides of the triangles are in proportion:
<em>cross multiply</em>
<em>use distributive property</em>
<em>subtract 10y from both sides</em>
<em>divide both sides by 5</em>
<em>cross multiply</em>
<em>divide both sides by 8</em>
Answer:
Point D and It is equivalent to 75%
Step-by-step explanation:
The first pipe pumps out
while the second pipe pumps out
So together, both pipes pump out
That is, with both pipes filling the tank, it should take 32 minutes total.