Use the elimination method to solve the following system of equations
2x+y=7
6x-y=9

x=2

Step-by-step explanation:

We see that there is already a common variable that can be canceled out -- y. y+(-y)=0! (Alternatively you may also multiply an equation by negative 1 and do subtraction, but in this case it's already done for you)

So now we just do some addition.

2x+6x=8x

y+(-y)=0

7+9=16

This means that 8x=16. Now we solve!

(Divide both sides by 8)

We're left with x=2 :)

∠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°