57. For an sosceles triangle ABC, which of the following statement is/are not sufficient to calculate the angle of A?
Statement (1) Angle C is 120 degrees
Statement (II): Angle B is 40 degrees
A Statement (1) alone is sufficient
B. Statement (II) alone is sufficient
C. Statements (1) and (II) together are sufficient
D. Statements (1) and (II) together are not sufficient

for any of you who need the translation here it is

step-by-step explanation:

find the angular size of the equatorial radius of the earth, if the horizontal parallax of the sun

they are simplified

step-by-step explanation:

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18