The nth equation is 3780 - 39n
Answer:
x(x−9)
Step-by-step explanation:
x2−9x
=x(x−9)
Answer:
17 adult shirts were sold
Step-by-step explanation:
x = adult shirts and y = children shirts
x + y = 40......adult shirts + child shirts = 40 total shirts
17x + 13y = 588...$ 17 for each adult shirt (x) + $ 13 for each child shirt (y) = $ 588
these are the equations we will be using.
now lets rearrange the first one....x + y = 40......x = 40 - y.....now sub 40 - y in for x back into the second equation
17x + 13y = 588
17(40 - y) + 13y = 588
680 - 17y + 13y = 588
-17y + 13y = 588 - 680
-4y = - 92
y = -92/-4
y = 23 <=== so there were 23 child shirts sold
x + y = 40
x + 23 = 40
x = 40 - 23
x = 17 <===== and 17 adult shirts sold
check...
17x + 13y = 588
17(17) + 13(23) = 588
289 + 299 = 588
588 = 588 (correct)
X2 = x2 + 2x + 9 Now subtract x2 from both sides and you have
x2- x2 = x2 - x2 + 2x + 9 or 0 = 2x + 9 now subtract 9 from both sides so you can solve for x.
0 -9 = 2x -9...and you have -9 = 2x
Now solve for x by dividing both sides by 2 and you arrive at x = -4.5