Which pair shows equivalent expressions?
A.2(2/5x + 2)=2 2/5x + 1
B.2(2/5x + 2)=4/5x + 4
C.2(2/5x + 4)=4/5x + 2
D.2(2/5x + 4)=2 2/5x + 8
Solution:

Let us distribute 2 inside the parenthesis.
That is, we use distributive property:
a(b+c)=ab+ac

So, 
Answer:Option (b)

Applying distributive property, a(b+c)=ab+ac



So, Option (B) is correct.
Complete Question
Kelvin finished 2/3 of his test in a 1/2 hour. Express this rate in hours per test.
Answer:
3/4 hours per test
Step-by-step explanation:
2/3 of his test = 1/2 hour
This rate in hours per test is calculated as:
x = 1/2 /2/3
x = 1/2 hour ÷ 2/3 test
x = 1/2 × 3/2
x = 3/4 hours per test
This rate in hours per test is given as 3/4 hours per test
Answer:
it should be (-8, -7)
Step-by-step explanation:
look up a coordinate plane
Answer:
dy/dx = (cos y + y sin x) / (cos x + x sin y)
Step-by-step explanation:
y cos x = x cos y
y (-sin x) + dy/dx cos x = x (-sin y dy/dx) + cos y
-y sin x + dy/dx cos x = -x sin y dy/dx + cos y
dy/dx (cos x + x sin y) = cos y + y sin x
dy/dx = (cos y + y sin x) / (cos x + x sin y)