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find exact value of x

129 is x

Step-by-step explanation:

Your equation would be like this x= 45 + 6=180 (180 because the sum of the angle measures in a triangle is 180 always)

so once you add 45+6 =51 the equation is now x=51=180 so you subtract 51 from both sides so it equals as this x=51=180

                                                                                         x =-51= -51

                                                                                         x=         129

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step-by-step explanation: