Answer:
-3
Step-by-step explanation:
2a - 6 = 4a
subtract 2a giving you -6 = 2a
divide by 2 from both sides so that a will be by itself
giving you -6 ÷ 2 = a
-6 ÷ 2 = -3
so a = -3
Hard to awnser a question if i cant understand what you are saying
Answer and Step-by-step explanation:
(a) Given that x and y is even, we want to prove that xy is also even.
For x and y to be even, x and y have to be a multiple of 2. Let x = 2k and y = 2p where k and p are real numbers. xy = 2k x 2p = 4kp = 2(2kp). The product is a multiple of 2, this means the number is also even. Hence xy is even when x and y are even.
(b) in reality, if an odd number multiplies and odd number, the result is also an odd number. Therefore, the question is wrong. I assume they wanted to ask for the proof that the product is also odd. If that's the case, then this is the proof:
Given that x and y are odd, we want to prove that xy is odd. For x and y to be odd, they have to be multiples of 2 with 1 added to it. Therefore, suppose x = 2k + 1 and y = 2p + 1 then xy = (2k + 1)(2p + 1) = 4kp + 2k + 2p + 1 = 2(kp + k + p) + 1. Let kp + k + p = q, then we have 2q + 1 which is also odd.
(c) Given that x is odd we want to prove that 3x is also odd. Firstly, we've proven above that xy is odd if x and y are odd. 3 is an odd number and we are told that x is odd. Therefore it follows from the second proof that 3x is also odd.
Answer:
= 8.9 units
Step-by-step explanation:
When a chord intersects with a tangent outside a circle then we use the relationship;
X ² = AO × BO, Where A and are the points of intersection of the chord an the circle, while O is the point of intersection between the chord and the tangent.
Therefore;
x² = 4 × 20 or 8 × 10
x² = 80
x = √80
= 8.944
≈ 8.9
