Y^2 - (y+5)^2 = 20
starting with (y+5)^2 that's y^2 + 5y + 5y + 25
then you change the signs and get
y^2 - y^2 - 10y - 25 = 20
so -10y = 45 >> 10y = -45 >> y = -4,5
answer: A
It's c . On the perpendicular bisector of the segment
Answer:
9
Step-by-step explanation:
cos(68°)×24= 8.99 which can be rounded to 9
Answer:
D
Step-by-step explanation:
For simplify the work we can start to factorise all the possibles expressions:
2x + 8.
8 is multiple of 2, so it can became
2(x+4)
x^2 - 16 this is a difference of two squares, so it can be rewritten as:
(x+4)(x-4)
x^2 + 8x + 16
we have to find two numbers whose sum is 8 and whose product is 16
the two number are 4 and 4
it becames:
(x+4)(x+4)
x+ 4 can‘t be simplified
if we look at the expression, we can find that x-4 appears at the numerator so
x^2 - 16 must be at numerator
but the second factor (x+4) doesn’t appear, so has been simplified. This situation can be possible only in the D option
in fact
(x+4)(x-4)/2(x+4) * (x+4)/(x+4)(x+4)
it became
(x+4)(x-4)/2 * 1/(x+4)(x+4)
(x-4)/2(x+4)
I am pretty sure your answer is going to be 243
I hope this helps, and good luck!!
