<span>у=-3х+5
1) 8 = -3x+5
-3x = 3
x = -1
2) y = -3*(-1) +5
y = 3+5
y = 8
3) 2 = -3x +5
-3x = -3
x=1
5 = -3x +5
-3x = 0
x = 0 </span>
7*4.2 - 7*5.2 + 3= 7 * (4.2-5.2)+3 = 7 * (-1)+3= -7+3=-4
9х-27 + 8х=7
9х + 8х = 7+27
17х=34
х= 17/34
х=0,5
sin(π/10 - x/2) = √2/2
π/10 - x/2 = (-1)^narcsin(√2/2) + πn, n∈Z
π/10 - x/2 = (-1)^n(π/4) + πn, n∈Z
x/2 = π/10 - (-1)^n(π/4) + πn, n∈Z
x = π/5 - (-1)^n(π/2) + 2πn, n∈Z
(a-b)(a+b)(a⁴+b²+b⁴)=(a²-b²)(a⁴+b²+b⁴)=a⁶-b⁶
(y-3)(y²+3y+9)-y(y-3)(y+3)-(y+3)²=y³-3³-y(y²-3²)-(y²+6y+3²)=
= y³-27- y³+9y - y²- 6y- 9 = 3y-36=3(y-12)