Answer:
nah its a.
Step-by-step explanation:
bakit?(#boyinthebrainly)
Let x = your number.
x^2 - 21 = 4x. Subtract 4x from both sides.
x^2 - 4x - 21 = 0. Factor.
(x - 7) (x + 3) = 0. Set each term to 0.
x + 3 = 0. Subtract 3 from both sides.
x = -3. This is the negative solution.
Set the other term equal to zero.
x - 7 = 0. Add 7 to each side.
x = 7. This is the positive solution.
An expression to represent a decimal between 1 and 10 multiplied by ten. basically to write larger numbers with less digits.
ex . 100 = 1 x 10^2
ex. 4321= 4.321 x 10^3
This one is super difficult, I see your struggle but the answer is A.
