1.26x + 3.58 = 1.74x + 6.46 решите уравнение

Question

Алгебра: 1.26x + 3.58 = 1.74x + 6.46 решите уравнение

SanchesMaster · Accepted Answer

1а) 5y(3y–2)–(y–1)(y+1)=15y^2-10y-y^2+1=14y^2-10y+1
1б) (d–8)(d+4)+(d–5)^2=d^2+4d-8d-32+d^2-10d+25=2d^2-14d-7
1в) 6(c+d)^2–12cd=6(c^2+2cd+d^2)-12cd=6c^2+6d^2
2a) b^3–36b=b(b-6)(b+6)
2б) –2а^2+8ab–8b^2=-2(a^2-4ab+4b^2)=-2(a-2b)(a-2b)
3) (b+3)^2(b–3)+3(b+3)(b–3)=(b^2-9)(b+3)+3(b^2-9)=b^3+3b^2-9b-27+3b^2-27=b^3+6b^2-9b-54
при b=-2 получается:
-8+24+18-54=34-54=-20
4a) (у–3)^2–16у^2=(y-3-4y)(y-3+4y)=(-3y-3)(5y-3)
4б) x^2–y^2–y–x=(x-y)(x+y)-(x+y)=(x+y)(x-y-1)
5) a^4–1=(a–1)(a^3+a^2+a+1)
a^4-1=a^4+a^3+a^2+a-a^3-a^2-a-1=a^4-1

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