Ineed with all the blank ones (15 points)

x = -7, A = 65 degrees

Step-by-step explanation:

[It is important to know that in any triangle, the sum of all three angles is equal to 180 degrees]

Therefore,

x + 72 + x + 51 + 71 = 180

2x + 194 = 180 [collect like terms]

2x = -14 [subtract 194 from both sides]

x = -7 [divide both sides by 2]

To find A, we substitute the value of x into x + 72:

A = (-7) + 72

A = 65 degrees.

Hope this helps! :D