Answer:
10
Step-by-step explanation:
I took this quiz yrs ago
COMPLETING THE SQUARE (PROCESS):
Do a reverse factoring procedure to develop the following form of equation:
(t + a)^2 = b
where:
t = unknown variable
a = coefficient
b = coefficient
Then take square root of both sides to find value of unknown variable as follows:
t^2 + 10t = 75
(t^2 + 10t + 25) = 75 + 25
(t^2 + 5t + 5t + 25) = 100
(t + 5)(t + 5) = 100
(t + 5)^2 = 100
√(t + 5)^2 = √100
Two solutions exist:
+(t + 5) = 10
AND
-(t + 5) = 10
Thus:
t = 10 - 5 = 5
AND
t = -5 - 10 = -15
Answer:
t = 5
AND
t = -15
The national interest rate on houses for 25 years is 4.3%. The banker wishes to test that the local interest rates are lower than the national rate. So he should use the initial data of 4.3% interest as his base data. Then he should investigate the rates of houses in the local vicinities and compare it to his base data.