Which of the following is an identity?
A. sinBsecBcotB = 1
B. sinBsecBcotB = cotB
C. sinBsecBcotB = sin²B/cos²B

tan A - sec A =
A. Sin^2A - cosA/cosA
B. sinA-1/cosA
C. cos^2A - 1/cosA

1/1 - sinA + 1/1 + sinA =
A. 2 cos^2 A
B. 2 sec^2 A
C. tan^2 A
D. cot^2 A

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

3x + 4y -25 =0 represents the amount of change sianna should recieve

answer: i literally just answered this question but they want me to do it again

step-by-step explanation: