jawaban nya lengkap pakai cara, kerjakan nomer 1-5

aku juga gk ngerti cuma mau dapat poin

1. 5a+4+7a+8 = 180
    12a + 12 = 190
    12a = 180-12
    12a = 168
        a = 168/12
        a = 14
ABD = 5a+4 = 5(14) + 4
                     =  70+4
                     = 74°
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3. Nilai x 
= x+5x+3x = 180
= 9x = 180
= x = 180/9
= x = 20
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Semoga membantu :_