Answer:
6.6
Step-by-step explanation:
1 hour equals 60 minutes. 60 minutes decided by 9 cookies is 6.6 minutes per cookie
Answer:
B
Step-by-step explanation:
Given the 2 equations
4x + 3y = 16 → (1)
7x + 6y = 31 → (2)
Multiplying (1) by - 2 and adding to (2) will eliminate the term in y
- 8x - 6y = - 32 → (3)
Add (2) and (3) term by term
- x = - 1 ( multiply both sides by - 1 )
x = 1
Substitute x = 1 in either of the 2 equations and solve for y
Substituting in (1)
4(1) + 3y = 16
4 + 3y = 16 ( subtract 4 from both sides )
3y = 12 ( divide both sides by 3 )
y = 4
Solution is (1, 4 ) → B
Answer:
x=-1, x=3 e x=2i, x=-2i
Step-by-step explanation:
Solve for x over the real numbers:
x^4 - 2 x^3 + x^2 - 8 x - 12 = 0
The left hand side factors into a product with three terms:
(x - 3) (x + 1) (x^2 + 4) = 0
Split into three equations:
x - 3 = 0 or x + 1 = 0 or x^2 + 4 = 0
Add 3 to both sides:
x = 3 or x + 1 = 0 or x^2 + 4 = 0
Subtract 1 from both sides:
x = 3 or x = -1 or x^2 + 4 = 0
Subtract 4 from both sides:
x = 3 or x = -1 or x^2 = -4
x^2 = -4 has no solution since for all x on the real line, x^2 >=0 and -4<0:
Answer: |
| x = 3 or x = -1
