X² + y² = 225
x - 7y = -75
x = 7y - 75
x² + y² = 225
(7y-75)² + y² = 225
(7y - 75)(7y - 75) + y² = 225
49y² - 525y - 525y + 5625 + y² = 225
50y² - 1050y + 5400 = 0
50(y² - 21y + 108) = 0
y² - 21y + 108 ⇒ (y - 12)(y - 9)
x = 7(12) - 75
x = 84 - 75
x = 9 ⇒ (9,12)
x = 7(9) - 75
x = 63 - 75
x = -12 ⇒ (-12,9)
4x - 2y = 10
-2y = -4x + 10
y = 4/2x - 10/2
y = 2x - 5 <==
Now, we know that 90°< θ <180°, that simply means the angle θ is in the II quadrant, where sine is positive and cosine is negative.
Answer:
4x(squared)-36
Step-by-step explanation:
=(2x+−6)(2x+6)
=(2x)(2x)+(2x)(6)+(−6)(2x)+(−6)(6)
=4x^2+12x−12x−36
=4x^2 −36
