помогите пожалуйста (:​

Ответ:

Объяснение:

(6a+7b)/(3a-4b)

1) (6*20+7*12)/(3*20-4*12) = (120+84)/(60-48)= 204/12 = 17

2) (6*10.8+7*6)/(3*10.8-4*6) = (64.8+42)/(32.4-24) = 106.8/8.4 = 1068/84 = 12 60/84 = 12 5/7

3) (6*2.4+7*0.8)/(3*2.4-4*0.8) = (14.4+5.6)/(7.2-3.2) = 20/4 = 5

4) (6*12+7*5.6)/(3*12-4*5.6) = (72+39.2)/(36-22.4) = 111.2/13.6 = 1112/136 = 8 24/136 =          8 3/17