X^2 + 11x - 5x + 55= X^2 +6X + 55
1. (5·a+4·b)²–(5–4·b)²=(5а)^2+2*5а*4b+ (4b)^2-(5^2-2*5*4b+(4b)^2)=25a^2+40ab+16b^2-25+40b-16b^2=25a^2+40ab+40b-25
2. (10·p–3·q)²+(5·p+6)²=100p^2-60pq+9q^2+25p^2+60p+36=125p^2-60pq+60p+9q^2
3. t·(9·t–1)²–81·t·(t–4)²= t(81t^2-18t+1)-81t(t^2-8t+16)=81t^3-18t^2+t-81t^3+648t^2-16*81t=630t^2-1295t
4. 5·m·n–2·(3·m–n)²+9·m²= 5mn-2(9m^2-6mn+n^2)=5mn-18m^2+12mn-2n^2= -18m^2+17mn-2n^2
Ну как то так :/Не 100 \% правильно, но всё таки...
Y=-3/8x+15
y=5/6x+73
-3/8x+15=5/6x+73
-9/24x+15=20/24x+73
-9/24x-20/24x=73-15
-29/24x=58:(-29/24)
x=48
y=-3/8*48+15
y=-18+15
y=-3
-3+48p=0
48p=3:48
p=1/16