5 а)0,75
б) 0,5
6) рисунка нету не могу решить
7) а) 1/3
б) 0,5
в) 1/6
г) 1/6
У= kx+b
x+y =2 ⇒ y= -x + 2
-2x+y = -3 ⇒ y=2x - 3
ax +by +c =0
y=-3.5x + 6 ⇒ 3.5x + y - 6 = 0
3x-4y=7
A(3,4) ⇒ x=3 , y=4
3*3 - 4*4 = 9 -16 = - 7 ≠ 7
ответ: не проходит график через точку А(3,4)
3. х= 7+18 = 25
4. 5х–7+х=4х–9
6х–4х=7–9
2х=–2
х=–1
5. 4а+8–(3–2а)=23
4а+8–3+2а=23
6а=23–5
6а=18
а=3
6. (2х+3)(4х–3)–17=2х(4х+1)
8х^2–6х+12х–9–17=8х^2+2х
6х–2х=26
4х=26
х=6,5
7. (х+1)/2 – (х–1)/3 = 3 |•6
3(х+1) – 2(х–1) = 18
3х+3–2х+2 = 18
х = 18–5 = 13
8. 2(х+1)^2 – (х–3)(х+3) = 7+х^2
2(х^2+2х+1) – х^2 + 9 – х^2 = 7
2х^2+4х+2–2х^2 = 7–9
4х = –2–2
4х = –4
х= –1
-5x(x-2)+(x-3)(5x+1)= -5x²+10x+5x²+x-15x-3= 10x+x-15x-3= -4x-3.
3a(a-b)-(a+b)(3a-b)= 3a²-3ab-(3a²-ab+3ab-b²)= 3a²-3ab-(3a²+2ab-b²)= 3a²-3ab-3a²-2ab+b²= -3ab-2ab+b² = -5ab+b².
(2a-b)(3a+b)+(3a-5b)(a-b)= 6a²+2ab-3ab-b²+3a²-3ab-5ab+5b²= 9a²-9ab+4b².
(5x²y-y)(x-2y)-(x²+2y)(5x-3y)= 5x³y-10x²y²-xy+2y²-(5x³-3x²y+10xy-6y²)= 5x³y-10x²y²-xy+2y²-5x³+3x²y-10xy+6y²= 5x³y-10x²y²-11xy+8y²<span>-5x³+3x²y.
3a(a+3)+(2-a)(3a-4)= 3a</span>²+9a+6a+8+3a²+4a= 9a+6a-8+4a= 19a-8.
7x²(x-2y)-(x-y)(7x+y)=7x²-14xy-(7x²+xy-7xy-y²)= 7x²-14xy-(7x²-6xy-y²)= 7x²-14xy-7x²+6xy+y²= -14xy+6xy+y²= -8xy+y².
(3m-2n)(2m-3n)+(3n-m)(2n-m)= 6m²-9mn+4mn+6n²+6n²-3mn-2mn+m²= 7m²-18mn+12n².
(2a-5b²)(a+b)-(b²-2a)(a-5b)= 2a²+2ab-5ab²-5b³-(ab²-5b³-2a²+10ab)= <span>2a²+2ab-5ab²-5b³-ab</span>²+5b³+2a²-10ab= 4a²-8ab-6ab².
