Answer:
A (0,3)
Step-by-step explanation:
The given trapezoid has vertices:
(0,6), (7,12), (7,9) and (0,12).
We want to choose from the given options, a point that is a vertex for the image produced by a dilation about the origin with a scale factor of 1/2.
Note that the mapping for such a dilation is:

This implies that:




Therefore correct choice is (0,3)
Answer:
The third angle of the triangle is 70°.
Step-by-step explanation:
The two angles of a triangle (say Δ ABC) are given to be 30° and 80°.
We have to find the third angle.
Let us assume that ∠ A = 30° and ∠ B = 80°, then we have to find ∠ C.
Now, we know that, ∠ A + ∠ B + ∠ C = 180° {Property of a triangle}
⇒ 30° + 80° + ∠ C = 180°
⇒ ∠ C = 180° - 30° - 80° = 70°
Therefore, the third angle of the triangle is 70°. (Answer)
For b it's 39 because you multiply 5 and 7 giving you 35 then add 4 Wich equals 39. I might be incorrect. check it out.
Answer: 2√2 - 3Explanation:The expession written properly is:

To rationalize that kind of expressions, this is to eliminate the radicals on the denominator you use conjugate rationalization.
That is, you have to multiply both numerator and denominator times the conjugate of the denominator.
The conjugate of √3+√6 is √3 - √6, so let's do it:

To help you with the solution of that expression, I will show each part.
1) Numerator: (√3 - √6) . (√3 - √6) = (√3 - √6)^2 = (√3)^2 - 2√3√6 + (√6)^2 =
= 3 - 2√18 + 6 = 9 - 6√2.
2) Denominator: (√3 + √6).(√3 - √6) = (√3)^2 - (√6)^2 = 3 - 6 = - 3
3) Then the resulting expression is:
9 - 6√2
-----------
-3
Which can be further simplified, dividing by - 3
-3 + 2√2
Answer: 2√2 - 3