1)(9a^2-4b^2)/(2b+3a)^2=(3a-2b)(3a+2b)/(2b+3a)^2 = (3a-2b)(2b+3a)
2)
{25x+2y=50
{5x-2y=-6
{2y=50-25x
{5x-50+25x=-6
{30x=44
{x=22/15
{y=20/3
3) b30=31
b31=32
q=b31/b30=32/31
4) V3.5*V2.1/V0.15=V49=7
<span>x²-3x-10>0
D=9+40=49 </span>√D=7
x₁=(3+7)/2=5
x₂=(3-7)/2=-2
___+____-2____-______5______+_____
x∈(-∞;-2)∪(5;+∞)
1 7/9 - 4/9=1 3/9
1/4*1 3/9=1/4*12/9=3/9=1/3
4 2/3+1/3=5
<span>решите уравнение
1)2x²-13x+6=0
D=13²-4*2*6=169-48=121=11²
x₁=(13-11)/4=0.5
x₂=(13+11)/4=6
2)2x²-11x-21=0
D=11²+4*2*21=289=17²
x₁=(11-17)/4=-1.5
x₂=(11+17)/4=7
решите неравенства
<span>1)5x²+4x-9≤0</span>D=4²+4*5*9=196=14²
x₁=(-4+14)/10=1
x₂=(-4-14)/10=-1.8(x-1)(x+1.8)≤0
\\\\\\\\\\\\\\\\\\\\
_______-1.8_________1______________
+ - +
x∈[-1.8; 1]
</span><span><span>
2)3y²-7y-10>0
</span>D=7²+4*3*7=169=13²
y₁=(7-13)/6=-1
y₂=(7+13)/6=10/3
(y-10/3)(y+1)>0
\\\\\\\\\\\\\\\\\\\\ \\\\\\\\\\\\\\\\\\\\\\\\\\\
__________-1_____________10/3______________
+ - +
y∈(-∞; -1)∪(10/3; +∞)</span>