3,3-(x-6,7)=100
3,3-x+6,7=100
10-x=100
x=10-100
x=-90
167.
1) 1 - (√x)^3
2) (√a)^3 + 8
169.
2)(√a+√b)/(a√a + b√b) =(√a+√b)/((√a)^3 + (√b)^3) = (√a+√b)/(√a+√b)(a - √ab + b) = = 1/(a - √ab + b) = (a - √ab + b)^ -1
а10-а4=-90 a1+9d-a1-3d=-90 6d=-90 d=-15
a6=-55 a1+5d=-55 a1+5*(-15)=-55 a1=-55+75=20
Всего = 120
коэф = 120 / 5 + 3 = 120 / 8 = 15
мальчишки = 15 * 5 = 75
девчонки = 15 * 3 = 120 - 75 = 45
Ответ: Б
-1.2b-6/5b+2=12/5b+2=-4/5+2=-2/5