When 21 is subtracted from the square of a number, the result is 4 times the number. Find the negative solution.

x = - 3

Step-by-step explanation:

x² - 21 = 4x

x² - 4x - 21 = 0

(x + 3) (x - 7) = 0

x = -3 or x = 7

answer: im gonna go with milli

step-by-step explanation:

yes

step-by-step explanation:

so of course you want to start by plugging the 5 in which goes to 7(5)+3(5)=50 because 7*5=35 and 3*5=15 and then add them together, then plug in the 5 to the other equation as well 9(5)+5=50 because 9*5= 45 and then add 5 and so yes they are equivalent.