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.
Answer:
20/7 or 2 and 6/7
Step-by-step explanation:
This equation works out to 2/1 • 10/7, which we can easily see equals 20/7, or 2 and 6/7, by multiplying the numerators and denominators.
Answer: B: 16 inches
Step-by-step explanation: dont got one
im in seventh grade :)
I think it’s y=2x-5 not sure tho
