Find m∠ABC.

(7x-1) (3x-9)

132°

19°

48°

21°

1 answer

To find m∠ABC, we need to set the sum of the two expressions equal to 180° since the angles in a triangle add up to 180°.

(7x-1) + (3x-9) = 180
10x - 10 = 180
10x = 190
x = 19

Then, we can plug in x = 19 into either expression to find m∠ABC:

7(19) - 1 = 133°
3(19) - 9 = 48°

m∠ABC = 133°.