Answer:
Step-by-step explanation:
13) x⁴-12x² +36
(a-b)² = a²-2ab+b²
a = x² ; b = 6
(x²)² - 2 * x² * 6 + 6² = (x² - 6)²
14) w⁴- 14w² - 32 = w⁴+ 2w² - 16w² - 32 = w² (w² + 2) - 16 (w²+2)
= (w² + 2) (w² -16 )
15) k³ + 7k² - 44k = k ( k² + 7k -44) = k ( k+11 ) ( k-4 )
16) 2a³ +28a²+96a =2a(a²+14a+48) = 2a(a+6)(a+8)
17) -x³ +4x² +21x = (-x) ( x² - 4x - 21) = (-x)(x-7)(x+3)
18) m⁶ - 7m⁴ -18m² = m² ( m⁴-7m²-18) = m² (m²-9)(m²+9)
= m² (m+1) (m-1)(m²+9)
19) 9y⁶ +6y⁴ + y²= y² ( 9y⁴+6y²+1) = y² (3y²+1)²
20) 8c⁴+10c² -3 = (4c +1)(2c-3)
![\bf \textit{difference and sum of cubes} \\\\ a^3+b^3 = (a+b)(a^2-ab+b^2) ~\hfill a^3-b^3 = (a-b)(a^2+ab+b^2) \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \boxed{a^6+b^6}\implies a^{2\cdot 3}+b^{2\cdot 3}\implies (a^2)^3+(b^2)^3 \\[2em] [a^2+b^2] [(a^2)^2-a^2b^2+(b^2)^2]\implies \boxed{(a^2+b^2)(a^4-a^2b^2+b^4)}](https://tex.z-dn.net/?f=%5Cbf%20%5Ctextit%7Bdifference%20and%20sum%20of%20cubes%7D%20%5C%5C%5C%5C%20a%5E3%2Bb%5E3%20%3D%20%28a%2Bb%29%28a%5E2-ab%2Bb%5E2%29%20~%5Chfill%20a%5E3-b%5E3%20%3D%20%28a-b%29%28a%5E2%2Bab%2Bb%5E2%29%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20%5Cboxed%7Ba%5E6%2Bb%5E6%7D%5Cimplies%20a%5E%7B2%5Ccdot%203%7D%2Bb%5E%7B2%5Ccdot%203%7D%5Cimplies%20%28a%5E2%29%5E3%2B%28b%5E2%29%5E3%20%5C%5C%5B2em%5D%20%5Ba%5E2%2Bb%5E2%5D%20%5B%28a%5E2%29%5E2-a%5E2b%5E2%2B%28b%5E2%29%5E2%5D%5Cimplies%20%5Cboxed%7B%28a%5E2%2Bb%5E2%29%28a%5E4-a%5E2b%5E2%2Bb%5E4%29%7D)
about the second one... well, is a "fait accompli" that using the pythagorean theorem, if x = 8 and y = 5, the hypotenuse must be √(8² + 5²) = √(89), which is neither of those choices.
5, 8, 13 are no dice, namely 5² + 8² ≠ 13
25, 64, 17 is are no dice too, because 25² + 17² ≠ 64²
however, 5,12 and 13 are indeed a pythagorean triple
also is 39, 80, 89.
when looking for a pythagorean triple, recall that c² = a² + b².
so the longest leg is the sum of the square of the small ones.
so what you'd do is, check the small legs, square them, add them up, if they're indeed a pythagorean triple, they "must" add up to the longest leg.
Answer;
Sean got 24 points
Katie got 31 points
Kevin got 8 points
Emily got 12 points
Sorry I cannot give proper explanation because of typo issues.
Hope that can help.
12a) yes, there will be two vanilla cupcakes left over after the baker makes ten more.