Answer:
1843:6754.9709254546.,657675
Step-by-step explanation:
The answer for this problem is 1661
Average speed = total distances / total time
3115.8 / 7.2 = 432.75 mi/h
The <em>correct answer</em> is:
An identity is an equation that is true for all real numbers.
Explanation:
An identity is a mathematical statement that is always true. It does not matter what numbers you substitute in for the variables, the result will be the same.
Answer:
Option A is correct, i.e. x = -3, x = 7.
Step-by-step explanation:
Given the equation is x² -4x -21 = 0.
We can compare it with general quadratic equation i.e. ax² +bx +c =0.
then a = 1, b = -4, c = -21.
We can use Quadratic formula as follows:-
x = ( -b ± √(b²-4ac) )/2a
x = ( +4 ± √(16-4*1*-21) )/2*1
x = ( +4 ± √(16+84) )/2
x = ( +4 ± √(100) )/2
x = ( +4 ± 10 )/2
x = (4+10)/2 or x = (4-10)/2
x = 14/2 or x = -6/2
x = 7 or x = -3
Hence, option A is correct, i.e. x = -3, x = 7.
