Answer:
Step-by-step explanation:
2y + 100 +6x-10=180(in a cyclic quadrilateral opposite angles are supplementary)
2y+6x+90 =180
2y + 6x = 90
dividing each side by 2
y+3x = 45 ........1
7x+1+2y+74 =180 ( same reason)
7x + 2y =105 ............2
multiplying 1 by 2
2y +6x =90........ 3
subtracting 3 from 2
7x+2y-2y-6x = 105-90
x = 15
substituting x=15 in 1
y+45 =45
y= 0
please mark me as the brainliest
Answer:
No this is not the same as cos(2Ф)
Step-by-step explanation:
First I changed the 
Ф into 1-
Ф
I then foiled the (1-2Ф)(1-Ф) and that resulted in 1-Ф-2Ф+2
Ф
From there, I then cancelled the two 2Ф and combined like terms and was left with 1-3Ф
Now 1-3Ф ≠ cos(2Ф)
20^2 + (x-8)^2 = x^2
x^2 = 400 + x^2 -16x + 64
16x = 464
x = 29 = hypotenuse
Double - Check
29^2 = 20^2 + 21^2
841 = 400 + 441
Answer:
Step-by-step explanation:
It depends on the systems of equations. I would stay away from elimination, go for substitution and graph only if asked.
