51) 5x-1=0 and x+6=0
5x=1, x=1/5 and x=-6
2 solutions x=1/5 and x=-6
52)x(2x+3)=0
2x=0 and 2x+3 =0
x=0 and x=-3/2=-1.5
53) x(5x-1)=0
x=0 and 5x-1=0
x=0 and x=1/5
54) z(4z+7) =0
z=0 and 4z+7=0
z=0 and z= - 7/4 = -1.75
z=0 and z=-1.75
X^2 - 25 is a difference of squares which has a special factorization.
In general, a^2 - b^2 = (a + b)(a - b)
x^2 - 25 = 0
(x + 5)(x - 5) = 0
x + 5 = 0 or x - 5 = 0
x = -5 or x = 5
Answer:
Sampling is necessary because researchers in the social sciences almost never have enough resources — time or money — to collect information about the entire set of subjects of interest to them.
Step-by-step explanation:
Sampling is done because you usually cannot gather data from the entire population. Even in relatively small populations, the data may be needed urgently, and including everyone in the population in your data collection may take too long.
Answer:
244
Step-by-step explanation:
