1.
а) 3b+(5a–7b) = 3b+5a–7b = 5a–4b
б) –(8c–4) +4 = –8c+4+4 = 8–8c
в) (2+3x) +(7x–2) = 2+3x+7x–2 = 10x
г) 3(8m–4)+6m = 3×8m–3×4+6m=24m–12+6m=30m–12
д) 15–5(1–a)–6a = 15–5–5a–6a= 10–11a
е) (2a–7y)–(5a–7) = 2a–7y–5a+7 = –3a–7y±7
ж) 14b–(15b+y)–(y+10b) = 14b–15b–y–y–10b = –11b–2y
з) 7(5a+8)–11a–58 = 7×5a+7×8–11a–58 = 35a+56–11a–58 = 24a–2
и) 9x+3(15–8x)–35 = 9x+3×15–3×8x–35 = 9x+45–24x–35 = 10–15x
к) 33–8(11b–1) –2b = 33–8×11b–8–2b = 33–88b–8–2b = 25–90b
2.
а) 0,7b+0,3(b–5) = 0,7b+0,3b–0,3×5 = b–1,5 = –0,81–1,5 = –2,31
б) (y–7)–(14–y) = y–7–14+y = 2y–21 = –0,6–21= –21,6
Объяснение:
Алгебра мой конёк)
Надеюсь
1.
а) 3b+(5a–7b) = 3b+5a–7b = 5a–4b
б) –(8c–4) +4 = –8c+4+4 = 8–8c
в) (2+3x) +(7x–2) = 2+3x+7x–2 = 10x
г) 3(8m–4)+6m = 3×8m–3×4+6m=24m–12+6m=30m–12
д) 15–5(1–a)–6a = 15–5–5a–6a= 10–11a
е) (2a–7y)–(5a–7) = 2a–7y–5a+7 = –3a–7y±7
ж) 14b–(15b+y)–(y+10b) = 14b–15b–y–y–10b = –11b–2y
з) 7(5a+8)–11a–58 = 7×5a+7×8–11a–58 = 35a+56–11a–58 = 24a–2
и) 9x+3(15–8x)–35 = 9x+3×15–3×8x–35 = 9x+45–24x–35 = 10–15x
к) 33–8(11b–1) –2b = 33–8×11b–8–2b = 33–88b–8–2b = 25–90b
2.
а) 0,7b+0,3(b–5) = 0,7b+0,3b–0,3×5 = b–1,5 = –0,81–1,5 = –2,31
б) (y–7)–(14–y) = y–7–14+y = 2y–21 = –0,6–21= –21,6
Объяснение:
Алгебра мой конёк)
Надеюсь
1) 2sin x-1=0
sinx = 1/2
x = (-1)^n arcsin(1/2) + πk, k∈Z
x = (-1)^n (π/6) + πk, k∈Z
2) cos(2x+П/6)+1=0
cos(2x+П/6) = - 1
2x+П/6 = π + 2πn, n∈Z
2x = π - π/6 + 2πn, n∈Z
2x = 5π/6 + 2πn, n∈Z
x = 5π/12 + πn, n∈Z
3) 6sin²x - 5cosx + 5 = 0
6(1 - cos²x) - 5cosx + 5 = 0
6 - 6cos²x - 5cosx + 5 = 0
6cos²x + 5cosx - 11 = 0
cosx = t, ItI ≤ 1
6t² + 5t - 11 = 0
D = 25 + 4*6*11 = 289
t₁ = (- 5 - 17)/12
t₁ = - 22/12
t₁ = -11/6
t₁ = - 1 (5/6) не удовлетворяет условию ItI ≤ 1
t₂ = (- 5 + 11)/12
t₂ = 1/2
cosx = 1/2
x = (+ -)arccos(1/2) + 2πm, m∈Z
x = (+ -) *(π/3) + 2πm, m∈Z