Answer:
∠B = 41°
Step-by-step explanation:
∠BCD is an exterior angle of the triangle
The exterior angle is equal to the sum of the 2 opposite interior angles, thus
∠A + ∠B = 113
72 + ∠B = 113 ( subtract 72 from both sides )
∠B = 41°
For x^2-49
this is a diffarence of two perfect squares. I suggest that this is memorised.
a^2-b^2=(a-b)(a+b)
so x^2-7^2=(x-7)(x+7)
so to solve x^2+x-56 you want to find out what two numbers add to 1 and multiply to make -56
since -56 is negative we know that the two number are difarent signs so that eliminatess answers B and D.
if we try answer C -8+7=-1 so the answer is not C because we want +1 not -1
then we see that 8+(-7)=1 so the answer is A
Answer:
38:81
Step-by-step explanation:
There are a total of 81 Astronauts in the space program.
Out of these, 43 are in outer space.
We are to determine the ratio of the number of astronauts on Earth to the total number of astronauts.
Number of Astronauts on Earth = Total Number - Number in Outer Space
=81-43 = 38
Therefore:
Number of astronauts on Earth : The total number of astronauts. = 38:81
