Answer:
Step-by-step explanation:
4y - 2(5 - y + 4) = 4y - 2(9 - y)
= 4y + 9*(-2) - y *(-2)
= 4y - 18 + 2y {Combine like terms 4y and 2y}
= 6y - 18
6y - 18 = 6*y - 6*3
= 6(y - 3)
6y- 18 = 2 *3y - 2*9
= 2(3y -9)
2(3y - 9) and 6(y- 3 ) are equivalent to 4y - 2(5- y +4)
Others are not equivalent
Answer:

Step-by-step explanation:
Hi!
Lets call:
T = temprature of the object
T₀ = temperature of surroundings
t = time
The rate of change of T is its derivative with respecto to time. If T > T₀, the object looses heat, so T decreases. Then, being k > 0:

In this case T₀ = 70ºF and k = 0.05/min. Then the differential equation is:

Answer:
58.5
Step-by-step explanation:
This expression should be simplified using order of operations. According to order of operations or PEMDAS, complete any numbers in parenthesis then any exponents, multiplication, division, additions and subtraction moving left to right through each operation.
Begin with Parenthesis.
(7+3-4*9) - Multiply first
(7+3-36) - Then add/subtract left to right
10 - 36 = -26
Replace -26 where the parenthesis were in the original expression.
9/4 (-26)
234/4
58.5
Answer:
35 mm.
Step-by-step explanation:
That would be (26 + 44)/2
= 70/2
= 35 mm.