Answer:
see explanation
Step-by-step explanation:
Given
x² - 3x - 40 = 0
Consider the factors of the constant term (- 40) which sum to give the coefficient of the x- term (- 3)
The factors are - 8 and + 5, since
- 8 × 5 = - 40 and - 8 + 5 = - 3, thus
(x - 8)(x + 5) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 8 = 0 ⇒ x = 8
x + 5 = 0 ⇒ x = 5
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Given
4x² - 81 = 0 ← this is a difference of squares and factors in general as
a² - b² = (a + b)(a - b), thus
4x² - 81
=(2x)² - 9²
= (2x + 9)(2x - 9) = 0 ← in factored form
Equate each factor to zero and solve for x
2x + 9 = 0 ⇒ 2x = - 9 ⇒ x = - 
2x - 9 = 0 ⇒ 2x = 9 ⇒ x = 
YOU DON"T HAVE TO YELL
512 PER STUDENT
BASICALLY,
CUBES NEEDED=CUBES PER STUDENT TIMES NUMBER OF STUDENTS
NUMBER OF STUDENTS=28+25=53
CUBES PER STUDENT=512
CUBES NEEDED=512 TIMES 53 EQUALS 27136 CUBES
SHE NEEDS 27136 CUBES FOR ALL HER STUDENTS
4 for part A
17 for part B
Hello Bubbleshi !
The first step you need to do is get everything in like terms.
- 1/6 and - 7 /4
Look at the denominator (number on the bottom)
6 and 4 go into 12, so lets check that out.
-1/6 , how can we get 12 from the denominator? Multiply it by 2.
So you multiply both the numerator (number on the top) and the denominator.
-1/6 becomes -2/12.
With -7/4, you want to get the 4 as a 12 (like terms!) so once again you multiply it by 3, and multiply the numerator as well.
-7/4 becomes -21/12.
-2/12 + (-21/12) is your final form of the problem.
You add -2 and -21 in the numerator, which is -23.
So its -23/12 which is your final answer.
Let me know if you need any more help!