Solve for b by elimination 2a+3b=12
5a-b=13

2a+3b=12

               b=(12-2a)/3

5a-b=13

b= -13+5a

Step-by-step explanation:

1) 2a+3b=12

-2a        -2a

3b=12-2a

/3         /3

b= (12-2a)/3

2) 5a-b=13

   -5a     -5a

-b=13-5a    

*-1   *-1   -b= 13(-1)-5a(-1) *you'd multiply by -1 to cancel out the negative on b*

b= -13+5a

step-by-step explanation:

x^2 -12x + 36 + y^2 = 36

x^2 + y^2 = 12x

r^2 = 12rcos(theta)

r = 12 cos(theta)

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value