Answer:
15?
Step-by-step explanation:
The factors of 21 are 1, 3, 7, and 21
Answer:
I think 8
Step-by-step explanation:
9/2 and 5/8
here 8 is the LCM.
so, 9/2 × 4/4
5/8 × 1/1
which gives: 36/8 and 5/8
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
