If mangle upper a upper o upper c= 85°, mangle upper b upper o upper c = 2x + 10, and mangle upper a upper o upper b = 4x – 15, find the degree measure of angle upper b upper o upper cand angle upper a upper o upper b. the diagram is not to scale.
angle upper a upper o upper c is shown. point b is located on the interior of the angle in between upper a and upper c. ray upper o upper b is drawn.
a. mangle upper b upper o upper c= 30°; mangle upper a upper o upper b= 55°
b. mangle upper b upper o upper c= 40°; mangle upper a upper o upper b= 45°
c. mangle upper b upper o upper c= 45°; mangle upper a upper o upper b= 40°
d. mangle upper b upper o upper c= 55°; mangle upper a upper o upper b= 30°

step-by-step explanation:

it's is b

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.