Answer:
140
Step-by-step explanation:
When working HCF and LCM problems, I like to think in terms of this little diagram:
(a [ b ) c]
It shows me one of the numbers is ab, the other is bc, the HCF is b and the LCM is abc. "a" and "c" must be relatively prime for "b" to be the HCF.
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Here, we're given ...
b = 20
ab = 320
abc = 2240
Then ...
c = abc/(ab) = 2240/320 = 7
x = bc = 20(7) . . . . . . equivalently, x = (abc·b)/(ab) = (2240·20)/320
x = 140
Answer:
x=40
Step-by-step explanation:
Both angles are equal. So the equation needs to equal 156.
Just plug in points for x until the answer is 156.
In this case, when we plug in 40, it works!

Answer:
C.
and 
Step-by-step explanation:
The proportion between these fractions is true. Multiply 4/10 (numerator and denominator) by 2.5 to get 10/25. This is the only correct option.
Hope it helps!
Answer:
3.
Step-by-step explanation:
Implicit differentiation:
x^2 y + (xy)^3 + 3x = 0
x^2 y + x^3y^3 + 3x = 0
Using the product rule:
2x* y + x^2*dy/dx + 3x^2 y^3 + x^3* (d(y^3)/dx) + 3 = 0
2xy + x^2 dy/dx + 3x^2 y^3 + x^3* 3y^2 dy/dx + 3 = 0
dy/dx(x^2 + 3y^2x^3) = (-2xy - 3x^2y^3 - 3)
dy/dx= (-2xy - 3x^2y^3 - 3) / (x^2 + 3y^2x^3)
At the point (-1, 3).
the derivative = (6 - 81 - 3)/(1 -27)
= -78/-26
= 3.