3х — 5y = 30
3х — 2y = 21
What is x and what is y

x=5, y = -3

Step-by-step explanation:

3х — 5y = 30

3х — 2y = 21

Subtract the two equation to eliminate x

3х — 5y = 30

-3х + 2y = -21

     -3y = 9

Divide by -3

-3y/-3 = 9/-3

y = -3

Now find x

3x -2(-3) = 21

3x+6 = 21

Subtract 6 from each side

3x+6-6 = 21-6

3x= 15

Divide by 3

3x/3 = 15/3

x = 5

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°